Jax

Jax is a shop NPC located near the Archery Range in the Village at who sells arrow-related items to the player.

Interface
You were not able to sell items to this NPC, but this was patched on the 22nd of June, 2022.

Quest
After first talking to Jax, the player can go in the room to his left and start a shooting quest. The player must remain on the elevated pressure plate the entire time whilst shooting at the targets (redstone lamps) around the room. After completing the first quest, the player will gain access to Jax's shop. After that, the time to complete a round of shooting all the targets gets shorter, but allows players to purchase better Arrows from Jax's shop. After completing all 3 quests, you will unlock Practice Mode, which asks you to shoot at the targets as fast as you can.

Tips
You can use a shortbow (Artisanal Shortbow, Juju Shortbow or Terminator), pairing with Bonus Attack Speed increasing to complete the quest more easily.