@Anuj_Singh : Okay, Do you have hybrid setup ? what exchange version do you have on-premises ? To get this functionality working you need to have hybrid setup with exchange server 2016 CU3 or later. Next you need to have oauth setup with office 365. Here is a reference article :
https://jaapwesselius.com/2020/04/07/microsoft-teams-and-exchange-2016/
The article includes references to technet documentation to follow. That being said the article is a bit old and things have changed slightly with new version of hybrid setup. IF you have latest CU on-premises and you run hybrid, oauth is setup automatically and the feature starts working automatically. Please note that there is a significant delay in replication these days with this setup. So once you have set this up wait for 24 hours at least to be sure.
