diff --git a/src/libs/Notification/LocalNotification/BrowserNotifications.js b/src/libs/Notification/LocalNotification/BrowserNotifications.ts
similarity index 77%
rename from src/libs/Notification/LocalNotification/BrowserNotifications.js
rename to src/libs/Notification/LocalNotification/BrowserNotifications.ts
index 20d9be48d915..dd07ddbb5e33 100644
--- a/src/libs/Notification/LocalNotification/BrowserNotifications.js
+++ b/src/libs/Notification/LocalNotification/BrowserNotifications.ts
@@ -1,18 +1,16 @@
 // Web and desktop implementation only. Do not import for direct use. Use LocalNotification.
-import _ from 'underscore';
 import EXPENSIFY_ICON_URL from '@assets/images/expensify-logo-round-clearspace.png';
 import * as ReportUtils from '@libs/ReportUtils';
 import * as AppUpdate from '@userActions/AppUpdate';
 import focusApp from './focusApp';
+import {PushParams, ReportCommentParams} from './types';
 
 const DEFAULT_DELAY = 4000;
 
 /**
  * Checks if the user has granted permission to show browser notifications
- *
- * @return {Promise}
  */
-function canUseBrowserNotifications() {
+function canUseBrowserNotifications(): Promise<boolean> {
     return new Promise((resolve) => {
         // They have no browser notifications so we can't use this feature
         if (!window.Notification) {
@@ -36,18 +34,9 @@ function canUseBrowserNotifications() {
 /**
  * Light abstraction around browser push notifications.
  * Checks for permission before determining whether to send.
- *
- * @param {Object} params
- * @param {String} params.title
- * @param {String} params.body
- * @param {String} [params.icon] Path to icon
- * @param {Number} [params.delay]
- * @param {Function} [params.onClick]
- * @param {String} [params.tag]
- *
- * @return {Promise} - resolves with Notification object or undefined
+ * @return resolves with Notification object or undefined
  */
-function push({title, body, delay = DEFAULT_DELAY, onClick = () => {}, tag = '', icon}) {
+function push({title, body, delay = DEFAULT_DELAY, onClick = () => {}, tag = '', icon}: PushParams): Promise<void | Notification> {
     return new Promise((resolve) => {
         if (!title || !body) {
             throw new Error('BrowserNotification must include title and body parameter.');
@@ -62,7 +51,7 @@ function push({title, body, delay = DEFAULT_DELAY, onClick = () => {}, tag = '',
             const notification = new Notification(title, {
                 body,
                 tag,
-                icon,
+                icon: String(icon),
             });
 
             // If we pass in a delay param greater than 0 the notification
@@ -91,24 +80,19 @@ function push({title, body, delay = DEFAULT_DELAY, onClick = () => {}, tag = '',
 export default {
     /**
      * Create a report comment notification
-     *
-     * @param {Object} params
-     * @param {Object} params.report
-     * @param {Object} params.reportAction
-     * @param {Function} params.onClick
-     * @param {Boolean} usesIcon true if notification uses right circular icon
+     * @param usesIcon true if notification uses right circular icon
      */
-    pushReportCommentNotification({report, reportAction, onClick}, usesIcon = false) {
-        let title;
-        let body;
+    pushReportCommentNotification({report, reportAction, onClick}: ReportCommentParams, usesIcon = false) {
+        let title: string | undefined;
+        let body: string | undefined;
 
         const isChatRoom = ReportUtils.isChatRoom(report);
 
         const {person, message} = reportAction;
-        const plainTextPerson = _.map(person, (f) => f.text).join();
+        const plainTextPerson = person?.map((f) => f.text).join();
 
         // Specifically target the comment part of the message
-        const plainTextMessage = (_.find(message, (f) => f.type === 'COMMENT') || {}).text;
+        const plainTextMessage = message?.find((f) => f.type === 'COMMENT')?.text;
 
         if (isChatRoom) {
             const roomName = ReportUtils.getReportName(report);
@@ -120,7 +104,7 @@ export default {
         }
 
         push({
-            title,
+            title: title ?? '',
             body,
             delay: 0,
             onClick,
@@ -128,9 +112,9 @@ export default {
         });
     },
 
-    pushModifiedExpenseNotification({reportAction, onClick}, usesIcon = false) {
+    pushModifiedExpenseNotification({reportAction, onClick}: ReportCommentParams, usesIcon = false) {
         push({
-            title: _.map(reportAction.person, (f) => f.text).join(', '),
+            title: reportAction.person?.map((f) => f.text).join(', ') ?? '',
             body: ReportUtils.getModifiedExpenseMessage(reportAction),
             delay: 0,
             onClick,
diff --git a/src/libs/Notification/LocalNotification/focusApp/index.desktop.js b/src/libs/Notification/LocalNotification/focusApp/index.desktop.ts
similarity index 59%
rename from src/libs/Notification/LocalNotification/focusApp/index.desktop.js
rename to src/libs/Notification/LocalNotification/focusApp/index.desktop.ts
index f00c72dc1af8..2b6f01457f44 100644
--- a/src/libs/Notification/LocalNotification/focusApp/index.desktop.js
+++ b/src/libs/Notification/LocalNotification/focusApp/index.desktop.ts
@@ -1,5 +1,8 @@
 import ELECTRON_EVENTS from '../../../../../desktop/ELECTRON_EVENTS';
+import FocusApp from './types';
 
-export default () => {
+const focusApp: FocusApp = () => {
     window.electron.send(ELECTRON_EVENTS.REQUEST_FOCUS_APP);
 };
+
+export default focusApp;
diff --git a/src/libs/Notification/LocalNotification/focusApp/index.ts b/src/libs/Notification/LocalNotification/focusApp/index.ts
new file mode 100644
index 000000000000..8504fde1bcb2
--- /dev/null
+++ b/src/libs/Notification/LocalNotification/focusApp/index.ts
@@ -0,0 +1,6 @@
+import FocusApp from './types';
+
+// On web this is up to the browser that shows the notifications
+const focusApp: FocusApp = () => {};
+
+export default focusApp;
diff --git a/src/libs/Notification/LocalNotification/focusApp/index.website.js b/src/libs/Notification/LocalNotification/focusApp/index.website.js
deleted file mode 100644
index ce7439d94cc3..000000000000
--- a/src/libs/Notification/LocalNotification/focusApp/index.website.js
+++ /dev/null
@@ -1,2 +0,0 @@
-// On web this is up to the browser that shows the notifications
-export default () => {};
diff --git a/src/libs/Notification/LocalNotification/focusApp/types.ts b/src/libs/Notification/LocalNotification/focusApp/types.ts
new file mode 100644
index 000000000000..534b7500fc71
--- /dev/null
+++ b/src/libs/Notification/LocalNotification/focusApp/types.ts
@@ -0,0 +1,3 @@
+type FocusApp = () => void;
+
+export default FocusApp;
diff --git a/src/libs/Notification/LocalNotification/index.desktop.js b/src/libs/Notification/LocalNotification/index.desktop.ts
similarity index 64%
rename from src/libs/Notification/LocalNotification/index.desktop.js
rename to src/libs/Notification/LocalNotification/index.desktop.ts
index a70141e7d9db..1576fefe2118 100644
--- a/src/libs/Notification/LocalNotification/index.desktop.js
+++ b/src/libs/Notification/LocalNotification/index.desktop.ts
@@ -1,12 +1,7 @@
 import BrowserNotifications from './BrowserNotifications';
+import {LocalNotificationModule, ReportCommentParams} from './types';
 
-/**
- * @param {Object} options
- * @param {Object} options.report
- * @param {Object} options.reportAction
- * @param {Function} options.onClick
- */
-function showCommentNotification({report, reportAction, onClick}) {
+function showCommentNotification({report, reportAction, onClick}: ReportCommentParams) {
     BrowserNotifications.pushReportCommentNotification({report, reportAction, onClick});
 }
 
@@ -14,18 +9,14 @@ function showUpdateAvailableNotification() {
     BrowserNotifications.pushUpdateAvailableNotification();
 }
 
-/**
- * @param {Object} options
- * @param {Object} options.report
- * @param {Object} options.reportAction
- * @param {Function} options.onClick
- */
-function showModifiedExpenseNotification({report, reportAction, onClick}) {
+function showModifiedExpenseNotification({report, reportAction, onClick}: ReportCommentParams) {
     BrowserNotifications.pushModifiedExpenseNotification({report, reportAction, onClick});
 }
 
-export default {
+const LocalNotification: LocalNotificationModule = {
     showCommentNotification,
     showUpdateAvailableNotification,
     showModifiedExpenseNotification,
 };
+
+export default LocalNotification;
diff --git a/src/libs/Notification/LocalNotification/index.native.js b/src/libs/Notification/LocalNotification/index.native.ts
similarity index 61%
rename from src/libs/Notification/LocalNotification/index.native.js
rename to src/libs/Notification/LocalNotification/index.native.ts
index 1f1771e619a5..b23378b6875a 100644
--- a/src/libs/Notification/LocalNotification/index.native.js
+++ b/src/libs/Notification/LocalNotification/index.native.ts
@@ -1,6 +1,10 @@
+import {LocalNotificationModule} from './types';
+
 // Local Notifications are not currently supported on mobile so we'll just noop here.
-export default {
+const LocalNotification: LocalNotificationModule = {
     showCommentNotification: () => {},
     showUpdateAvailableNotification: () => {},
     showModifiedExpenseNotification: () => {},
 };
+
+export default LocalNotification;
diff --git a/src/libs/Notification/LocalNotification/index.website.js b/src/libs/Notification/LocalNotification/index.ts
similarity index 64%
rename from src/libs/Notification/LocalNotification/index.website.js
rename to src/libs/Notification/LocalNotification/index.ts
index 0ecb8bcbb81d..69c1ccaacf4e 100644
--- a/src/libs/Notification/LocalNotification/index.website.js
+++ b/src/libs/Notification/LocalNotification/index.ts
@@ -1,12 +1,7 @@
 import BrowserNotifications from './BrowserNotifications';
+import {LocalNotificationModule, ReportCommentParams} from './types';
 
-/**
- * @param {Object} options
- * @param {Object} options.report
- * @param {Object} options.reportAction
- * @param {Function} options.onClick
- */
-function showCommentNotification({report, reportAction, onClick}) {
+function showCommentNotification({report, reportAction, onClick}: ReportCommentParams) {
     BrowserNotifications.pushReportCommentNotification({report, reportAction, onClick}, true);
 }
 
@@ -14,18 +9,14 @@ function showUpdateAvailableNotification() {
     BrowserNotifications.pushUpdateAvailableNotification();
 }
 
-/**
- * @param {Object} options
- * @param {Object} options.report
- * @param {Object} options.reportAction
- * @param {Function} options.onClick
- */
-function showModifiedExpenseNotification({report, reportAction, onClick}) {
+function showModifiedExpenseNotification({report, reportAction, onClick}: ReportCommentParams) {
     BrowserNotifications.pushModifiedExpenseNotification({report, reportAction, onClick}, true);
 }
 
-export default {
+const LocalNotification: LocalNotificationModule = {
     showCommentNotification,
     showUpdateAvailableNotification,
     showModifiedExpenseNotification,
 };
+
+export default LocalNotification;
diff --git a/src/libs/Notification/LocalNotification/types.ts b/src/libs/Notification/LocalNotification/types.ts
new file mode 100644
index 000000000000..25db8b080e2b
--- /dev/null
+++ b/src/libs/Notification/LocalNotification/types.ts
@@ -0,0 +1,25 @@
+import {ImageSourcePropType} from 'react-native';
+import {Report, ReportAction} from '@src/types/onyx';
+
+type PushParams = {
+    title: string;
+    body?: string;
+    icon?: string | ImageSourcePropType;
+    delay?: number;
+    onClick?: () => void;
+    tag?: string;
+};
+
+type ReportCommentParams = {
+    report: Report;
+    reportAction: ReportAction;
+    onClick: () => void;
+};
+
+type LocalNotificationModule = {
+    showCommentNotification: (reportCommentParams: ReportCommentParams) => void;
+    showUpdateAvailableNotification: () => void;
+    showModifiedExpenseNotification: (reportCommentParams: ReportCommentParams) => void;
+};
+
+export type {PushParams, ReportCommentParams, LocalNotificationModule};