On web interface of your Thinka, goto Settings -> Support, then "Start Remote Support Access", copy the number and share it with a Thinka support agent.
Or you can use the Thinka Setup App available from the Appstore. Start the app, select your Thinka and then click on 'Remote Access'. After enabling access you'll see a number that you can send to Thinka support by clicking on 'Share with support'.
Thinka support agents can now access your Thinka, until you disable access to it. No one else (even if they would have the number) but Thinka authorised personnel can access your Thinka.