find which port is in and PID use linux code example
Example 1: process runninng on particular port
sudo ss -lptn 'sport = :80'
Example 2: linux query port use by pid
$ sudo ss -lptn 'sport = :80'
State Local Address:Port Peer Address:Port
LISTEN 127.0.0.1:80 *:* users:(("nginx",pid=125004,fd=12))
LISTEN ::1:80 :::* users:(("nginx",pid=125004,fd=11))