I'm afraid the difficulty question is relative

Struggling to get Meteotemplate working. I think my issue, or basic misunderstanding, is about the server? Or where the data is coming from?
For something like Meteotemplate or Weewx, do I need a dedicated computer to link to? For example, Meteotemplate instructions ask for a domain? I think I am missing something critical there.
In my simple mind, I was expecting to be able to just put in my Wunderground or Ambient ID/API and send the data to a new platform that records and displays it. Is this not possible?
It seemed like this was what Weather Display offers, but I have not been successful in getting it to sync reliably.