You didn't tell me whether the door operates normally from the inside, which would be an important clue, so I'll give you all the possibilities.
Doorlock systems can fail, this is a common failure in any kind of car. If the key won't turn, the lock cylinder may have failed or needs lubrication. I like to use Liquid Wrench or TriFlow myself. If a little LW frees the lock, that's great. I like the TriFlow for a lubricant in a lock that works already. If it doesn't free the lock, then you may need a new lock cylinder.
If the lock turns freely with the key, and won't unlock the door, then probably the linkage clip broke and the linkage fell apart inside the door. This is easy to fix, you remove the doortrim panel and reassemble the linkage using a new clip.
If neither condition is the case, it's less common, but the latch may be defective which requires a new latch.
If you want to find a Dodge specialist, here's our directory link for you:
https://repairpal.com/directory?address=95765&car_bra...