Something isn't working with the template. Check Template:Twitter for similar, working template.

Template for linking to youtube pages/videos/profiles, shows the YT logo next to the link so it's clear it goes outside the wiki.

The template provides the youtube.com/ part of the url, so you need to copy the rest of the url after it. it uses the youtube.com/ instead of youtu.be/ so that links to profiles & playlists also work, not just links to videos.

Crash Course-playlist

{{yt|watch?v=IoyQs0Cv4p0&list=PLxYefyArg-d1wRWRpTfQMW0cmh32mQTbx|Roll20 Crash Course-playlist}}

If you copy the url part from a youtu.be/ link, add watch?v= in front of the string of characters.

Example: You have the link https://youtu.be/xKXpKIiB5WM to the "5 Roll20 Crash Course - Rolling Dice"-video, then the correct result will be {{yt|watch?v=xKXpKIiB5WM|Roll20 Crash Course - Rolling Dice}}, resulting in this: Crash Course - Rolling Dice

normal yt link Roll20 Crash course