I finally got this working. Thank you again for your reply.
I found the Google API dashboard very confusing. Something to note, for anyone else following this at home. As I worked my way down the Google form, it asks you to upload a logo image. DON’T do this.
If you upload an image, when you get to the bottom of the form and try to complete it you can click the button to save the entries. When you click Save, the Google page disables the Save button, showing that it accepted the save command. But it shows you a disabled Submit button, with a tooltip that says you can’t submit until you associate some sort of OAuth id with the request. No matter how much I Googled the message or explored the Google API pages I wasn’t able to figure out what it wanted me to create. The page also says that once you do manage to submit the request, the approval process may take weeks.
If you simply don’t upload a logo image, none of this happens. No disabled submit button. No approval process. It just works.
In addition, since we’re all using Auth0 here, it’s worth noting that Auth0 allows you to upload your logo image in the Auth0 settings. So the Auth0 login dialog that contains the Log in with Google button already contains your custom logo, so you don’t need one in Google.
As far as I can tell, the Google social login is now working with Auth0 in my app.