You can import any URL <x id="START_LINK"/>supported by youtube-dl<x id="CLOSE_LINK"/> or URL that points to a media file. You should make sure you have diffusion rights over the content it points to, otherwise it could cause legal trouble to yourself and your instance.
You can also synchronize a remote channel in <x id="START_LINK" ctype="x-a" equiv-text="<a routerLink="/my-library/video-channel-syncs">"/>your library<x id="CLOSE_LINK" ctype="x-a" equiv-text="</a>"/>