root@GL-AXT1800:~# nmap -sU -p 51820 hj82918.glddns.com
Starting Nmap 7.80 ( https://nmap.org ) at 2023-07-08 23:36 CDT
Nmap scan report for hj82918.glddns. com (143.244.220.150)
Host is up (0.052s latency).

PORT STATE SERVICE
51820/udp open|filtered unknown

Nmap done: 1 IP address (1 host up) scanned in 1.23 seconds