I found a working iptv m3u8 link which has loads of channels, it says in the description the services ends in a few weeks, the stream links are setup like this:
domain.com:80/live/userNameHere/PasswordHere/237.ts
that server must be getting it from somewhere, is it possible to get the source so incase this username expires, it can still be used?
Probably not. Judging from the link, they are most likely using xtream codes panel to restream from their server, so you will not see the original source link.