Mobile: Go to the YouTube app, open your video, 'Share', 'Copy link', then on your DiscordFox profile press 'Add' under 'Featured Videos' and paste the link in the text box, then edit it e.g. https://youtu.be/lSDvSYo6j18?si=nxmaGG3v0LIZZIuV -> lSDvSYo6j18
Desktop: Open video, copy the link into the box, then edit it e.g. https://www.youtube.com/watch?v=lSDvSYo6j18 -> lSDvSYo6j18
Contact me on Discord at inlieuofleu and I will get back to you as quickly as possible.