Which engine is this? Could be a 4 banger, most likely it’s the 258 I-6, but could also be a 304 V8…or could be any number of aftermarket swaps. The alternator’s mounted differently in each of the above, and it’s no help to show a picture without knowing which engine. But, all options revolve around the same principle. You’ll have two mounting holes on the alt, one will allow the alt to pivot, and the other will slide along an adjuster to tension the belt. And yeah, the 258 probably had one serpentine belt from the factory. You can rebuild that Jeep 5 times over from recyclers and Jeep specialists, so you can probably very easily find an entire assembly pretty reasonably. Other than that, you can probably manipulate a universal mount to get it to work.