Technically, your npub is already your channel. It looks like it uses blossom servers to store video, for playback. I've noticed that when i post a vid to Plebs, there's a note of the video in my amethyst feed. I'm hoping that as it develops, that note also contains the blossom link to the video. That way I'm posting across all of nostr, and I wouldn't have to post a separate note stating that I uploaded something to Plebs.