If u have the time and want to, can u explain everything step by step? I really never worked with querys and event dispatchers. I maybe should have mentioned, that u can have every item just once and its like fullfilling a Collectible-book, so it doesnt have to fill up a row of items until a new row in the inventory starts. The according button just should show up as soon as the item is granted to the player, the position of the item is already set in the inventory.
Ty u already helped me alot!