Issues Integrating AdMob in Cocos Creator 3.8.6

I’m using version 3.8.6 of Cocos Creator and have installed AdMob from the store. This is my first time working with AdMob, so my understanding is still limited. To use ads, I need to create nodes in the scene, which I call either from a defined script or via plugin integration. Upon building in Android Studio, I handle the implementation through the Java environment.

I am encountering some difficulties in this process and would appreciate any guidance. Has anyone successfully implemented AdMob in this setup?