Click edit on the page you wish to add the video to

Once editting the page find wher you want the video and edit the block by clicking the +:


Or if there is already a text box there, remove the text box first:


Once you click the "+" you will get a screen like this:


Select video player:


After selecting this you should get an edit pop up:


Add in the link to your video:


Once you've done this, just hit update on the right of the screen: