Does Sync Gateway user require Full Admin Role?

According to the documentation of Couchbase SyncGateway configuration file, the databases.this_db.username property is “The RBAC user’s username for authenticating to Couchbase Server”.

So I have the following question:

Should the user have Full Admin or Read Only Admin role?

This should be covered in the getting started guide under “STEP 2 — Create RBAC User”. The answer depends which Couchbase Server version you have, as newer ones have a specific role for Sync Gateway: