Hello and welcome to just answer Dodge. This is most likely a linkage that has become disconnected at the transfer case. This is an inexpensive repair and may not even involve any parts. You will need to get under the truck and look at the linkage while some one else moves the lever inside the cab. It should be pretty obvious as to where it became disconnected.
Hope this information helps, and let me know if you need more assistance with this.
There may be a retainer/clip that broke or came off. If you have basic mechanical skills you should be able to do this yourself. If not, then go to the dealer or even a good independent shop.