M4uhd.cx [Free Access]

"Watch movies on the m4uhd.cx website."

So, the correct phrase would be:

The proper article for the website would be "the". m4uhd.cx

"m4uhd.cx is one of the popular streaming sites." "Watch movies on the m4uhd

Or

I see you want to discuss the website "m4uhd.cx". m4uhd.cx