Just realised that latest self-hosted appsmith now uses a default cloud hosted endpoint (https://cs.appsmith.com) with a precreated client id for Oauth authorization for google sheet.
We cannot do that as we have strict policy on token management and we cannot leak our token into cloud env.
we need to use the old way of specifying our own client id and secret so the scope of the oauth is in our total control.
How do I do this?
@David You can connect to Google Sheet using our REST API interface instead of using the native integration - https://docs.appsmith.com/how-to-guides/oauth2-authorization-for-google-sheets
Thanks @dancia. Will take a look.
meanwhile, does it imply that for the operations such as add/query/remove, we will not be able to utilise the integrated ones and will need to compose the restapi json format manually?
@David Yes, I believe that’s the only way to retrieve and post data to Google Sheets in case you use the REST API plugin as specified in the doc shared above 
. I also noticed we have a feature request related to this - [Feature] Request for a GSheet plugin for self-hosted instance · Issue #5502 · appsmithorg/appsmith · GitHub
Will post your comments on that issue as well
Thanks Dancia.
Will keep an eye on that github issue.