Incase it's helpful for anyone, when the instructions talk about updating your MainActivity.class, it means the MainActivity.java file, and it'll need to look like this
package [YOUR_PACKAGE_ID_SHOULD_ALREADY_BE_HERE];
import android.os.Bundle;
import com.getcapacitor.BridgeActivity;
import com.openforge.capacitorgameconnect.CapacitorGameConnectPlugin;
public class MainActivity extends BridgeActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
registerPlugin(CapacitorGameConnectPlugin.class);
super.onCreate(savedInstanceState);
}
}
Incase it's helpful for anyone, when the instructions talk about updating your MainActivity.class, it means the MainActivity.java file, and it'll need to look like this