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.
Almost all users will give up your add-on immediately when they see the above error. To get verification, you need to send an OAuth Request via Google Cloud console. First of all, you need to write a clear and concise privacy policy like this. Here are all steps you need to know
1.Host privacy policy page in a trusted domain