This is a plugin I found recently and really enjoy. It gives you the opportunity to redirect several webpages to alternatives. For example Youtube to FreeTube or Piped. If I search for youtube in Firefox, FreeTube automatically opens and shows me my feed. I like it, I use it, I can recommend it.
Nevermind, I got it working.
Ok, still not right. Looks like I am going to have to fight. I have hope though. Will report back if I actually get it working.