Need help aligning ui elements

summary - Im trying to make the ui for the inventory and i need help aligning it

Basically what i would do is to create the background/base in blender cause i dont have photoshop and then adding importing them to ue5


(placeholder) The gray part is the background/base of the inventory and the black part is supposed to be a slot

what i was going to do is to get and image widget then use it as the image, i would then get a button and put it inside the slot and use the white box in order for the to be perfectly in the middle but when i tried to do that i realized just how difficult it was, so im wondering if there is any other way for aligning ui elements, i thought of maybe redesigning it to be so that all the parts are separate so that i can arrange them in any way that i want but i dont want it to be misaligned and i have thought of maybe editing the grid for widgets but i dont know how to

Sorry if i overcomplicated a simple problem and thank you in advance
and yes it is in 3d im not good with 2d art