The addon will need some scopes for working properly. For example, the Bulk Barcode QR Code Generator & Mail merge addon requires the script.external_request scope because this add-on will need to call a Paypal web service for showing all pricing options which user can choose. If you do not get OAuth approval from Google Cloud Platform/API Trust & Safety team, when user clicks “Authorize access” button, they will see a warning message this app isn't verified.
- You should host the website in the trusted domain and Google will verify it. I highly recommend to use [Google domain[(https://domains.google/)] because it is very cheap and it is very easy to be verified by Google Cloud.
2.Explain about all scopes
script.container.ui and script.external_request and spreadsheets
- Google will show the information which user can understand easily like this: