You might want to be a bit more specific as for what you want to achieve… is this only about using online trailers from Youtube?
From what I remember, Plex had already commented they cannot offer that for licensing reasons (or the lack of clarity who actually owns the content running through Youtube).
There’s an existing feature suggestion to include Youtube shows into the Web Shows feature.
If it’s a more generic “let’s play Youtube content through Plex” – Plex has discontinued the support for content channels/plugins some years ago
