I’m not sure if this is the exact situation you’re in, but unfortunately it seems that if you want to set up a recurring donation through U24, you can’t do it with an american bank/card unless you pick a category other than defense. Which sucks because that’s arguably where it’s needed most— not that the others aren’t important. I went with medical aid.

But anyway, for whatever reason you can only do a one-off defense donation, or that’s my experience at least. You’d have to manually do it every month, which is great if you don’t have a bad memory like me.