Turn around and get into a Reverse Whip position under the bar, at the frontend, hook your knees onto the bar and bring your upper body up to reach for the top catcher. Unhook your knees as you make the catch.
This trick is equivalent to the technique used during a Seat Jump or Seat Roll to get up to sitting. In this case, you are facing the other way and instead of grabbing the cables and sitting up, you grab the top catcher. Many people get up to sitting by hooking their knees on the bar and then trying to reach up for the cables (instead of the Whip position). You'll probably find that this (easier) technique for sitting up doesn't give you enough lift to make a top catch.
You can find out more about this trick in my books:
Thanks to the team at Circus Arts Australia for providing this video.