Is there a a tutorial on how I can set a TCP Port to a specific port like 43210?

Hi Mikrotik nation,

Im a newbie guy that 24/7 learning, im currently and trying to install SERVER AVATAR (a Server Dashboard) for a office, but it requires me to set a PORT to PORT 43210 which i have no idea.

Can anyone help or give me a clue on how will I start?
Thank you!

https://forum.mikrotik.com/viewtopic.php?p=908118
https://forum.mikrotik.com/viewtopic.php?t=179343