Hello @Hragab ,
Welcome to the Poly Community.
Our FAQ contains:
Jan 29, 2020 Question: Can I use any of the well-known configuration parameters or settings via the Web Interface to make changes to the Teams application running on Poly phones?
Resolution: Only fundamental settings regarding the network or others can be used. Nearly everything else is part of the Teams Android app running on the phone and Microsoft would need to be consulted.
Feb 10, 2020 Question: Can I customize the Teams application running on Poly phones?
Resolution: As explained above only our partner Microsoft can make changes to the UI. We can only suggest to check and vote >here<
Nov 26,2020 Question: Is there a way to suggest or request enhancements to the Microsoft supplied IP Phone Teams application?
Resolution: Please check >here<
As you hopefully understand there is no action from the Poly side as our Partner Microsoft supplies the Teams Android APK to us and other 3rd parties as is.
Please ensure to provide some feedback if this reply has helped you so other users can profit from your experience.
Yes, but not directly. Microsoft places the Sign Out menu under the openly available Settings menu on a Teams phone when the signed-in user is configured in the default User mode.
If you instead configure the user accounts signed into the phone to use either the Meeting or Common Area Phone mode then the Sign Out option is automatically placed behind Device Settings > Admin Only menu which is only accessible by knowing the device's admin password.
See this article for more details on configuring the modes: http://blog.schertz.name/2019/11/managing-microsoft-teams-phone-policies/