From videos in most places, hover your cursor over the bottom right side of the video.
Double click the 'Watch on Youtube' message or the 
icon.
That takes you to Youtube. When you get there, check the series of options below the video.
BTW, It's best to go to the individual video and not pick up the link from the Youtube channel page. Get there by clicking them there and going to the next window.
Click the Share option which opens a box a little bit below. It may or may not be highlighted. If it is, use the copy option in your browser's edit choices and paste the link into your message.
Preview how it comes up, and erase any extra letters and numbers, which usually begin with the & symbol.
That should post the video for you, without extra letters. To make it work within your message text, be sure to allow sufficient space.
I go back and forth to add any text supplied by the channel owner below the video.
Enjoy!
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