C++ conversion Problem

I’m new to C++ in Unreal and I am trying to set an int32 variable to the variable as can be seen in the picture but I have no idea how to make this function work. I’m trying
to get the value of the Maximum Item Stack Amount which is inside a struct which is inside a U_Master_Inventory_Item class. Any help would be great.

I have managed to progress but still have an issue.