Check out Bully locking tailgate handle. They are the best I have found. On my 2012 Ram 1500 R/T I went with the PopLock electric set up. Works with the normal door lock switches and the factory key fob. Took less than an hour to install.
https://www.ebay.com/itm/POP-N-LOCK-PL83...0/142111657534?