If you want your incoming calls to ring you and someone else (such as a delegate) at the same time, you can set that up in Teams.
Select Settings and more next to your profile picture at the top of Teams. Then choose Settings > Calls .
Under Call handling and forwarding > When you receive a call, you can choose to ring a contact, a call group, or your delegates.
If you choose to ring a new number or contact, begin typing the name of the person you'd like to simultaneously receive your calls and select their name from the dropdown.