Information
Automatically admitting dial-in users reduces control over who can participate in a meeting and increases potential for data breaches. This policy reduces the risk by requiring all dial-in users to wait in a lobby until they are admitted by an authorized meeting participant.
Solution
1. Sign in to the Microsoft Teams admin center.
2. Select Meetings > Meeting policies.
3. Select the Global (Org-wide default) policy.
4. Under the Meeting join & lobby section, set People dialing in can bypass the lobby to Off.