The ends of our pull-up bars are sealed with finishing caps. You can hardly see them, since we've almost perfectly matched the color of the caps to the pull-up bar. That makes it all the more annoying when one or more of the caps get damaged, for example, during a move.
Upon request, we'll send you new caps, see this blog post.
But as soon as you have them in your hand, the question comes up of how to get them into the ends of the pull-up bar. You can see how in this video here.
But I'll also write it right here, in case you read text faster than you watch videos: Take the cap, and hammer it into the end with a rubber mallet. Done.