Q.How To Grow Desert Rose? It Is About 4 Yrs Old-
it does nothing. I water as told, saturate and let it dry completely out; water again. It gets some sun in morning if not raining. Temp about 72o I have seen nothing cactus dirt and reg.

Certified GKH Gardening Expert
Likely, it is a lack of sunlight. They will not bloom without full sun, or at least 6 to 8 hours of it per day.
There are a few other factors, but this is most likely.
Here are a couple of articles that will help:
https://www.gardeningknowhow.com/ornamental/flowers/desert-rose/desert-rose-not-blooming.htm
https://www.gardeningknowhow.com/ornamental/flowers/desert-rose/caring-for-desert-rose-plants.htm