Tridents, bows, fishing rods, and food items/potions/milk buckets are used while the trade menu is opened.

The following items:
Firstly, you muse open the trade UI from a villager/wandering trader.
• Tridents in the offhand will automatically throw itself.
• Bows in the offhand will automatically shoot an arrow.
• Fishing rods in the main/off-hand will throw the fishing bobber to the villager.
• Eating/drinking items will automatically be consumed as the animation plays.