Which slot to access, slots are listed below
1 = Inventory Holding
2 = Anvil Input
3 = Anvil Material
4 = Stone Cutter Input
5 = Trade2 Ingredient 1
6 = Trade2 Ingredient 2
7 = Trade Ingredient 1
8 = Trade Ingredient 2
10 = Loom Input
11 = Loom Dye
12 = Loom Material
13 = Cartography Input
14 = Cartography Additional
15 = Enchanting Input
16 = Enchanting Material
17 = Grindstone Input
18 = Grindstone Additional
28 = BeaconPayment
29 = Crafting 2x2 Input 1
30 = Crafting 2x2 Input 2
31 = Crafting 2x2 Input 3
32 = Crafting 2x2 Input 4
33 = Crafting 3x3 Input 1
34 = Crafting 3x3 Input 2
35 = Crafting 3x3 Input 3
36 = Crafting 3x3 Input 4
37 = Crafting 3x3 Input 5
38 = Crafting 3x3 Input 6
39 = Crafting 3x3 Input 7
40 = Crafting 3x3 Input 8
41 = Crafting 3x3 Input 9
51 = CreatedItemOutput
Returns the item in the specified UI slot or nil if the slot is empty