The audio conferencing pin allows you to start a MS Teams meeting by calling in rather than using the MS Teams app from a computer.  This effectively makes MS Teams behave like a simple audio conference bridge.


In Outlook, click on the schedule icon, then click on "New Teams Meeting".  In the resulting blank meeting invitation there will be a link in the meeting options.  CTL-CLICK that link.  Login if prompted with your email address and computer password.




You will then see this presented.   Click on the Reset Pin button.  A random pin will be generated for you.  Ensure that you remember your pin.






Now, if you start a Teams meeting from a phone rather than from the Teams application, as the meeting organizer, you can start the meeting with your Pin when prompted.