Please Please PLEASE create a lock-on key bind for controllers

I had a stroke in 2020. I cant play with mouse and keyboard because my left hand is still quite numb. I play with controller as that is much easier. All i ask is make a lock on target key bind that i can set for my controller so i can lock on to the main target instead of attacking some small target thats behind me. the auto targeting in this game gets me killed more often than anything else because instead of using my main attack on the main enemy i suddenly switch to someone thats not even on screen.