Did most everything right. Just put everything after the equal sign, excluding the equal sign itself.
Step 1: Enter this - "[you tube]" (Without the space in between, if I put it without the space, I would get that white box.) Step 2: Find the video that you are looking for and copy everything that comes after the equal sign. "=" It should be a series of numbers and letters. Step 3. Enter this: "[/you tube]" (Again without the space in between.)