Settings up ads

How can I setup ads in my game? I need it very simple where when you press a button, an ad is played.
I’ve seen unity manuals on this, and I found a general one, but then I found another for Android Studio, so I’m not sure what to do.
Btw I need this for android.

Try this one:

It’s for Google ad services, A.K.A. Google Admob. You’ll only need to write the show command in the OnClick event for your button.

Thanks for the reply, but I would really rather have UnityAds instead.
Have any idea how to do that?