Google Sign In difficulty

I’ve implemented the code for Google Sign In into my game app.

The window comes up asking me to select a Google account, this is good.

But after I make the selection, ON ANDROID, my code returns with Error Sign In 0. A ZERO.

Any idea what’s going on?

I found details here thanks to Scott: https://coronalabs.com/blog/2019/10/03/app-sign-in-for-your-corona-apps/ , however, the way the firestore plugin is mentioned there to be put into build.settings didn’t work because there were no supportedPlatforms included. So, I tried this and it worked:

  ["plugin.firestore"] = { publisherId = "tech.scotth", supportedPlatforms = { {iphone = true}, {android = true} } },