How to transfer Movies from Photos to Youtube

I am a bit stuck here, what is the easiest way to transfer/forward movies from Photos to Youtube? Today I will export my movie to the desktop from Photos and then drop it right on Youtube.
I guess it could be an easier way?
Any ideas?

Thank you Bowline!
But then I need to transfer the movie from Photos to iMovie and then to Youtube?
There is no third part software to send the “Photos Movie” direct to Youtube?