This is a working way. Who needs.
import android.content.Intent;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
public class CustomActivity extends AppCompatActivity{
private final String defoldActivityClassName = "com.dynamo.android.DefoldActivity";
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
// Processing intents
Class<?> gameActivityClass = null;
try {
gameActivityClass = Class.forName(defoldActivityClassName);
} catch(ClassNotFoundException ex) {
}
if (gameActivityClass != null)
{
Intent newIntent = new Intent(this, gameActivityClass);
startActivity(newIntent);
}
finish();
}
}