How to add Mattermost as Virtual Host on ASUSTOR NAS?

I want to add Mattermost on ASUSTOR NAS in virtual host

Steps to reproduce

Expected behavior
I had issues trying to set up a site URL on the system control page so I thought about setting this up on ASUSTORs Web Center as a virtual host, as I have done this before with a Node js/Google Script website.

Observed behavior
I was unable to use the default port of 8065 and was unable to find the installation path of Mattermost on the ASUSTOR NAS for the virtual host thing to work, so I am really lost here