HaF ~ in YouTube click the share and copy that url.
PHP Code:
https://youtu.be/IYzlVDlE72w
or from the address bar
https://www.youtube.com/watch?v=IYzlVDlE72w
To post the video use the YouTube button and the portion from above after the backslash or after the equal sign.
PHP Code:
[YT]IYzlVDlE72w[/YT]
If you are using the app ... I can't help you.