Why didn't this work the first time?
If it doesn't work it means for whatever reason the url tags weren't automatically applied. It's the same tag to post a link except you put the url name in between the url tags too. It should be automatically applied whether it's a video or not. If it's a video, it will automatically embed, if not, it will turn the url into a hyperlink.
To fix it, quote yourself where it worked and use those tags, but put the url you want in both spots...