Which Instagram links work
Any link to a public post or Reel: instagram.com/p/…, instagram.com/reel/…, the same links with a username in front, and the link the Instagram app copies when you tap Share. Tracking parameters on the end are fine.
What you get
ClipBeam shows the video or photo first, so you know it's the right one before you save it. Instagram videos come in a single quality — the one Instagram itself serves — so there is no resolution to pick.
Download saves the file to your device. On a phone, Share hands the file itself to another app, so the person you send it to doesn't need Instagram to watch it.
What doesn't work yet
Posts from private accounts, Stories and Highlights can't be read. Carousel posts with several photos or videos aren't supported yet either: ClipBeam takes one image or video per link.