You need to configure a toll-free dial in bridge for Teams meetings.

Purchase Communications Credits.

Assign a phone number to a resource account.

Get an auto attendant toll-free number.

Get a Dedicated conference bridge (Toll Free) number.

Purchase a Microsoft 365 Domestic and International Calling Plan license.

From the meeting policy, set Allow dial -in users to bypass the lobby to On.

Assign a phone number to the bridge.