What do you use as the redirect uri when doing google oauth

I'm trying to build an app in the ticket sidebar that requires google oauth to hit some of our backend apis via id_token. I'm running into issues with trying to do the redirect_uri as i keep getting the `redirect_uri_mismatch` on Google despite adding a few different urls going back to zendesk.

Does anybody have any configurations to share that utilize Google OAuth for a single page application (react app) as an iframe?