Thank you for your support, I appreciate it so much.
That is the link I originally provided in this post and what I was referencing I believe in the first place.
“Add Firebase SDK to your project” might sounds obvious to most on this forum. I’m not a developer and I didn’t realise I even needed to download and open Android Studio ! Just done that now for the first time!
Step 2 we are in Firebase downloading the google-services.json and then Step 3 I don’t even know what application I’m in, hence my confusion.
For a layman it’s tough to follow, but clear I’m sure for someone with a little more experience. I’ve completed all the missions to this point (thanks to the support from you guys) but perhaps this isn’t intended for complete novices.