A new feature in 2022 is GEAR. Your avatar (created legend) can now equip gear obtained from Event rewards or Mystery Boxes and include: Headwear, Tops, Bottoms, Shoes, Gloves, Eyewear and Bats .
From the Team menu, select My Legend > Gear
Tap the "i" for Information in the upper left of the gear screen.
You may upgrade an item with GEAR XP:
If you wish to trade in a piece of gear for Gear XP, UNEQUIP the item and tap "Trade Shop,"
Select the item (it will outline in green) and tap "Trade Item."