docs: [AXM-425] add docs for configure mobile push notifications

openedx/core/djangoapps/ace_common/docs/push_notifications_configuration.md

@@ -0,0 +1,62 @@
+# Configure mobile push notifications in edx-platform
+
+
+### 1. Create a new Firebase project
+
+All push notifications in Open edX are sent via FCM service to start with it you need to create
+a new Firebase project in Firebase console https://console.firebase.google.com/
+
+### 2. Provide service account credentials to initialize an FCM admin application in edx-platform
+
+To configure sending push notifications via FCM from edx-platform, you need to generate private
+key for Firebase admin SDK in Project settings > Service accounts section.
+
+After downloading .json key, you should mount it to LMS/CMS containers and specify a path to
+the mounted file using FIREBASE_CREDENTIALS_PATH settings
+[variable](https://github.com/openedx/edx-platform/pull/34971/files#diff-f694c479e5c9b133241a799e1ddf33d5d5133bfdec91e3f7d371e094c9999e74R31). There is also an alternative option,
+which is to add the value from the .json key to the FIREBASE_CREDENTIALS environment
+[variable](https://github.com/openedx/edx-platform/pull/34971/files#diff-f694c479e5c9b133241a799e1ddf33d5d5133bfdec91e3f7d371e094c9999e74R34),
+like a python dictionary.
+
+https://github.com/openedx/edx-ace/blob/master/docs/decisions/0002-push-notifications.rst?plain=1#L108
+
+
+### 3. Configure and build mobile applications
+
+Use the supported Open edX  mobile applications:
+
+https://github.com/openedx/openedx-app-android/
+
+https://github.com/openedx/openedx-app-ios
+
+#### 3.1 Configure oauth2
+
+First you need to configure Oauth applications for each mobile client in edx-platform. You should create separate
+entries for Android and IOS applications in the Django OAuth Toolkit > Applications.
+
+Fill in all required fields in the form:
+  - Client ID: <your_client_id>.
+  - Client type: Public
+  - Authorization grant type: Resource owner password-based
+  - Public Client secret: <your_client_secret
+  - Name: <your_app_name>
+
+Specify generated Client ID in mobile config.yaml file
+
+https://github.com/openedx/openedx-app-android/blob/main/Documentation/ConfigurationManagement.md#configuration-files
+
+https://github.com/openedx/openedx-app-ios/blob/main/Documentation/CONFIGURATION_MANAGEMENT.md#examples-of-config-files
+
+#### 3.2 Provide FCM credentials to the app
+
+Create new apps in Firebase Console for Android and IOS in Project settings > General section.
+
+Download credentials file, google-services.json for Android, or GoogleService-Info.plist for IOS.
+
+Copy/paste values from configuration file into config.yaml as shown in example configurations.
+
+https://github.com/openedx/openedx-app-android/blob/main/Documentation/ConfigurationManagement.md#configuration-files
+
+https://github.com/openedx/openedx-app-ios/blob/main/Documentation/CONFIGURATION_MANAGEMENT.md#examples-of-config-files
+
+Build applications and you’re ready to go!