Python reports an error:
RuntimeError: The server socket has failed to listen on any local network address. The server socket has failed to bind to [DESKTOP-7FQDOK8]:6699 (system error: 10048 - Only one usage of each socket address (protocol/network address/port) is normally permitted.).
Solution : The port is occupied by the same program running or a different program (6699 here). Just change the port to another value.