DeluxeMenu

To show an ItemsAdder item with custom texture on DeluxeMenu you have to add this special attribute to the icon of your menu:

nbt_int: CustomModelData: 1

Instead of 1 you have to set the CustomModelData of your custom item.

How to get the CustomModelData value?

You have to use the command /iatag while holding an ItemsAdder item, then search for CustomModelData value.