Sometimes, google shows the weird warning “ScriptError: Authorization is required to perform that action” when you try to access add on. It is a google issue. You should use the following steps to resolve this issue.
1. Sign out all gmail or G Suite accounts in the browser which you are using addon
2. Sign in your gmail
3. Setting up Third-party apps with account access
- Go to https://myaccount.google.com/security
- Click on Security tab
- Click on Third-party apps with account access

- Click on Manage third-party access
Choose the add on you are experiencing issue. For example, “Easy QR Code Generator for Form”, or “Bulk Barcode QR Code Generator” add on
- Click Remove access button to remove all permissions which you allowed for this add on in the past. Press OK button.

- Reinstall add on and you’ll need to grant access for the add on again.
- Refresh the Google Sheet or Google Form file
4. If you still experience this issues after following all above steps, please try to use different browser. If you use G Suite account, please ask your G Suite administrator to whilelist this addon