Targeting S+ (version 31 and above) requires that one of FLAG_IMMUTABLE or FLAG_MUTABLE be specified when creating a PendingIntent, On AlarmPingSender

Add the following to your build.gradle(app) dependencies.

dependencies {
  // For Java
  implementation 'androidx.work:work-runtime:2.7.1' 

  // For Kotlin
  implementation 'androidx.work:work-runtime-ktx:2.7.1'
}