Check Which Port Number a Process is Listening on

$ sudo ss -ltnp

State        Recv-Q        Send-Q                Local Address:Port                  Peer Address:Port
LISTEN       0             100                       127.0.0.1:25                         0.0.0.0:*            users:(("master",pid=3877,fd=13))
LISTEN       0             128                         0.0.0.0:443                        0.0.0.0:*            users:(("sshd",pid=4544,fd=3))
LISTEN       0             127                         0.0.0.0:988                        0.0.0.0:*
LISTEN       0             2                           0.0.0.0:3389                       0.0.0.0:*            users:(("xrdp",pid=4060,fd=11))
LISTEN       0             128                       127.0.0.1:38591                      0.0.0.0:*            users:(("containerd",pid=3748,fd=8))
LISTEN       0             128                         0.0.0.0:111                        0.0.0.0:*            users:(("rpcbind",pid=2704,fd=8))
LISTEN       0             128                         0.0.0.0:22                         0.0.0.0:*            users:(("sshd",pid=4544,fd=5))
LISTEN       0             2                         127.0.0.1:3350                       0.0.0.0:*            users:(("xrdp-sesman",pid=4049,fd=7))
LISTEN       0             50                                *:8443                             *:*            users:(("java",pid=5120,fd=145))
LISTEN       0             128                            [::]:443                           [::]:*            users:(("sshd",pid=4544,fd=4))
LISTEN       0             128                            [::]:111                           [::]:*            users:(("rpcbind",pid=2704,fd=11))
LISTEN       0             128                            [::]:22                            [::]:*            users:(("sshd",pid=4544,fd=6))

$ sudo lsof -i :443

[ec2-user@ip-172-16-0-86 ~]$ sudo lsof -i :443
COMMAND    PID     USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
nc        1756 ec2-user    3u  IPv4 510594      0t0  TCP ip-172-16-0-86.ca-central-1.compute.internal:49462->ip-192-168-0-48.ca-central-1.compute.internal:https (ESTABLISHED)
nc        1833 ec2-user    3u  IPv4 510842      0t0  TCP ip-172-16-0-86.ca-central-1.compute.internal:49536->ip-192-168-0-48.ca-central-1.compute.internal:https (ESTABLISHED)
nc        2466 ec2-user    3u  IPv4 514459      0t0  TCP ip-172-16-0-86.ca-central-1.compute.internal:50148->ip-192-168-0-48.ca-central-1.compute.internal:https (ESTABLISHED)
nc        2505 ec2-user    3u  IPv4 514590      0t0  TCP ip-172-16-0-86.ca-central-1.compute.internal:50164->ip-192-168-0-48.ca-central-1.compute.internal:https (ESTABLISHED)

[ec2-user@ip-172-16-0-86 ~]$ sudo fuser 443/tcp 

443/tcp: 4544