OK, I was looking for a picture and didn't find what I wanted, so here goes:
Put the strap through the tag. Open the end of the strap and feed the other end through the opening in thne strap. This should now firmly attach the strap to the tag.
Put the loose end through the luggage handle. Open that loose end. Feed the end with the attached tag through the open loop and pull tight (basically the same thing you did on the other end, just that you now have the tag attached.)
I hope that came across the way I intended it
Cheers.