use_up_stick.mcfunction

# Stores the current stack size of the item entity in the scoreboard.
execute as @s store result score @s item_stack_size run data get entity @s Item.Count

# The constant 1 is subtracted from the scoreboard value.
scoreboard players operation @s item_stack_size -= 1 constants

# Stores the now decremented scoreboard value back into the stack size of the item entity.
execute as @s store result entity @s Item.Count int 1 run scoreboard players get @s item_stack_size