can you post youtube videos on facebook using the code off the video?

I was able to do it with one of my notes like six months ago and now I’m posting notes and you can’t see the video….just the code that I pasted in.
I’d rather have people just watch the video right on the spot without having to copy & paste the website for the youtube video…

how come its not showing the video when it did before?!
please help what am i doing wrong.

May be, but i never try it:(