Looking for a step by step guide to push notifications with Firebase

Hi everyone, I want to implement push notifications in my app. I am using Firebase as backend and I have followed all tutorials I could find from AppGyver and on this forum, but I find it really hard to understand how it works. I would need someone who has done this before and could give me more guidance (sort of like a video call where we do things step by step together). Let me now if anyone could do this and I will set up an intro call!
Thanks a lot!

This might help you: