what do you mean? like how to post the video onto a post? ok lets see, you have the link to the videos
you have to take everything after this sign = and that would be QtxUGcSiyUk
then use these [ yt] QtxUGcSiyUk [ /yt] , but do not leave any space.
if anything comes after the the code, you dont include that. only after this sign = and until the code.
example for these kind of links
you only use this code zQ_uXjD3xNU. it comes after this sign = and stops at the last letter which is U, right before this sign &.