Certified GKH Gardening Expert
You, really, don't have to prune it unless there are diseased limbs, or to shape it up.
Another instance to prune will be when taking cuttings. Otherwise it is not completely necessary.
This article will give you more information on the care of these: https://www.gardeningknowhow.com/ornamental/flowers/desert-rose/desert-rose-propagation.htm