When you create a new data source on Data Studio for the first time, you need to enter the email that you signed up with on the Find My Insight member portal you will also need to copy the master token to authorize your account. The master token is a long string that you can find on your My Connectors page (the red block is masking it as per the screenshot below).
If you have to re-configure your connector ( this could be changing your account name from abc to abd ). It can take up to 10 minutes to sync your new configuration to Data Studio in the backend. Alternatively you can try to revoking access on Data Studio to force sync immediately as the second screenshot below.