The channel name is a unique identifier of your channel on this and all the other instances. It's as unique as an email address, which makes it easy for other people to interact with it.
If your instance is explicitly allowed by Twitter, a videoplayer will be embedded in the Twitter feed on PeerTube video share.<x id="LINE_BREAK" ctype="lb" equiv-text="<br />"/> If the instance is not, we use an image link card that will redirect to your PeerTube instance.<x id="LINE_BREAK" ctype="lb" equiv-text="<br />"/><x id="LINE_BREAK" ctype="lb" equiv-text="<br />"/> Check this checkbox, save the configuration and test with a videoURL of your instance (https://example.com/videos/watch/blabla) on <x id="START_LINK" ctype="x-a" equiv-text="<a target='_blank' rel='noopener noreferrer' href='https://cards-dev.twitter.com/validator'>"/>https://cards-dev.twitter.com/validator<x id="CLOSE_LINK" ctype="x-a" equiv-text="</a>"/> to see if you instance is allowed.