Port Conflict: MAMP PRO Says the Port for Apache or MySQL Is Already in Use
If MAMP PRO displays an error message saying the port you want to use for Apache, MySQL, or another service is already in use, it means another process is occupying the port. MAMP PRO will automatically suggest a different port.
To confirm if another process is running on the port (e.g., port 80), open the terminal and run the following command:
netstat -na | find "80"
For more information, refer to the official documentation.