Several changes I needed to get this compiling again

app/build.gradle

@@ -56,7 +56,7 @@ android {
 dependencies {
     implementation 'com.squareup:otto:1.3.8'
     implementation 'com.github.jberkel.k-9:k9mail-library:eaf689025e'
-    implementation 'com.android.billingclient:billing:2.0.3'
+    implementation 'com.android.billingclient:billing:2.1.0'
     implementation 'com.firebase:firebase-jobdispatcher:0.8.6'
     implementation 'androidx.annotation:annotation:1.1.0'
     implementation 'androidx.preference:preference:1.1.0'

build.gradle

@@ -2,6 +2,7 @@ buildscript {
     repositories {
         google()
         jcenter()
+        mavenCentral()
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:4.1.3'
@@ -18,8 +19,12 @@ allprojects {
 
     repositories {
         jcenter()
+        mavenCentral()
         maven { url "https://maven.google.com" }
         maven { url "https://jitpack.io" }
+        maven { url "https://jcenter.bintray.com" }
+        //  This is the only repo that seems to be hosting "com.firebase:firebase-jobdispatcher" in 2024
+        maven { url "https://maven.scijava.org/content/repositories/public/" }
         google()
     }
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,5 @@
-#Sat Apr 22 23:40:26 CDT 2023
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.2-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.5-all.zip