Problem to download apk, Firebase config file error

when i try to download the app i get a error and I get this message

Make sure you’ve uploaded firebase configuration file (google-services.json) in your assets.

i have got this but i dont undestand what do i have to put

Go to your firebase project and connect your app into it. After linking, you’ll get a json file named google-services.json . Download that and upload in Kodular project asset.

i dont undestand how to do it.

I need to become the developer of the play store account to obtain the missing data because I wanted to wait to see how the application is being shared before uploading it

Didn’t you set firebase token and URL on your app?

no, i have got this:

what is sopuse that i have to put in there?

Search community please. There are many threads explaining how to use firebase.