Imgur - Link not working?

[FlyingClayDisk]

Which icon is it exactly? It seems to want a URL if I’m using the correct one. What if I don’t have one, and it’s a screenshot from my device?

Additionally, I asked this previously in a thread but didn’t receive a reply. I see where to post a YouTube video. It also wants a URL. I’m doing it the way we did on ATS, with pasting everything after the = sign.

What am I doing wrong on these two items?

Thanks in advance!

It's the green icon on the right-most side of the 6th box from the right (in the radio buttons header). 
Regarding YT videos, I'm not positive, but I think it's the whole URL and the application resolves the rest (not positive on this one though).