Third-party authentication in Google Sheets add-on

[Tie Cheng]

Hello,

We have an Microsoft Excel add-on. Users need to sign up and sign in in the tool to use it. We provide third-party authentications such as Google and Microsoft. When users click on the button "Google authentication", a dialog is popped up where users can enter their Google ID and password. When the authentication succeeds, the dialog is closed and users sign in in the tool.

Now, we plan to make a Google Sheets add-on. As users in Google Sheets have already signed in with their Google account, we would like to know what's the conventional approach to use third-party authentication in a Google Sheets add-on. Precisely,

1. if add-ons provide Google authentication, does it ask users to re-enter their google ID and password?

2. Do add-ons usually use popups or dialogs to host third-party authentication?

Thank you

Tie