* Serving Flask app 'app'

 * Debug mode: on

Address already in use

Port 5000 is in use by another program. Either identify and stop that program, or start the server with a different port.

On macOS, try disabling the 'AirPlay Receiver' service from System Preferences -> Sharing.

라고 뜹니다. 해결 방법좀 알려주세요~