It supposed to be there, just like in the tutorial:
Welcome to the forums @ress15!
Does the plugin have a gdap configuration file? According to the documentation for Android plugins, it seems a gdap file is required for Godot to detect and load the plugin. (Disclaimer - I have very little experience with Android and Godot)
gdap
@TwistedTwigleg Thanks for the reply. I just realized that I put the Admob-plugin's folder in the "plugins" folder. The plugin supposed to be in the "plugins" folder without any other folder.