...
Learn about other limitations here.
Q: Can I invite non-OTC accounts to a meeting in Teams?
A: Yes, you can. Simply send the non-OTC email a link to your meeting, and they will be able to join it. Unlike OTC accounts, however, you will need to admit this third-party account into your meeting via the Participants menu. OTC accounts do not need to be admitted and join meetings automatically, provided they are logged in with their OTC account.