Is there a way to transfer sync gateway users to other server?
I’m assuming you are talking about multiple Sync Gateway clusters backed by their own Couchbase Server clusters? Because in a scenario where you have multiple sync gateways all connected to the same Couchbase Server cluster, this shouldn’t be needed.
Unfortunately there is no built in functionality to solve this, due to the SG User API not supporting revisions.
One way to solve this is to move the user storage into a centralized place like Active Directory, and use OpenID Connect in conjunction with Sync Gateway for user auth. See https://docs.couchbase.com/sync-gateway/2.1/authentication.html#openid-connect.