It depends on where the video is housed. If it's Vimeo, you can do Add Content > Document/Video > Vimeo and embed the link (same if it's YouTube)
It depends on where the other video is housed on how you add it to your Coop.
If it's Vimeo, you can do Add Content > Document/Video > Vimeo and embed the link (same if it's YouTube)
If it's just a link they give you, then the way I'd do it is by adding the link to a note. It's adding a hyperlink as you would anywhere else you are pasting a link. With a note, you have the flexibility to add images and text if you want to tell people what the link is they're clicking on.
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