Androidx MutliDex: The number of method references in a .dex file cannot exceed 64K

Modify the module-level build.gradle file to enable multidex and add the multidex library as a dependency, as shown here:

android {
    defaultConfig {
        ...
        minSdkVersion 16 
        targetSdkVersion 28
        multiDexEnabled true
    }
    ...
}

dependencies {
  implementation 'com.android.support:multidex:1.0.3'
}

If you do not override the Application class, edit your manifest file to set android:name in the tag as follows:

    <?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.example.myapp">
        <application
                android:name="android.support.multidex.MultiDexApplication" >
            ...
        </application>
</manifest>

If you do override the Application class, change it to extend MultiDexApplication (if possible) as follows:

...
import androidx.multidex.MultiDexApplication;
...
public class MyApplication extends MultiDexApplication { ... }

Or if you do override the Application class but it's not possible to change the base class, then you can instead override the attachBaseContext() method and call MultiDex.install(this) to enable multidex:

public class MyApplication extends SomeOtherApplication {
  @Override
  protected void attachBaseContext(Context base) {
     super.attachBaseContext(base);
     MultiDex.install(this);
  }
}