I was trying to modify some weapons, but I couldn't drag and drop on my phone or tablet. I don't have a computer so that's not an option. I have some modified weapons so I know I must have gotten it to work before, but I haven't played in a couple years so I don't remember how. If anyone knows how I can modify my weapons on a touch screen I would really appreciate it.

*Update: I figured it out! I was dumb, it was easy to do from my inventory.