Cannot setup floating action buttons as class cannot be found (Android Studio)

Question

So I am pretty new to android and I am trying to setup a floating action button with the Android Design Support Library using this guide in Android Studio.

My Projec

Answer 1

If you are using androidx, you need to use:

implementation 'com.google.android.material:material:1.2.1'

(or whatever latest version you want).

The action button in the XML looks like: