Personal Gmail OAuth Verification - Google need access to the app?

Hi,
I am trying to add a personal Gmail into scenarios, I have been through the documentation and added it. Google needed more justification for the scope requirements which I supplied and that was accepted.
Now the sticking points they need to test app functionality, they have sent me an email to add to the app.
How do I deal with this?
All I am doing to reading my own Gmail emails, sending to openai for classification and then adding a label.
Any advice please

Have you created a test user for your app in Google cloud console?

I have added the account gmail as the owner and added the email they requested as a viewer.