assuming you just can’t do what this linked website says about how to gift discord/nitro subs: https://support.discord.com/hc/en-us/articles/360020877112-Nitro-Gifting
personally don’t know what discord and or nitro are exactly but if you purchase from App Store what about just signing into your cousins Apple ID and add your debit/credit card to his / her wallet then purchase a sub then remove your debit / credit from his / her wallet app then sign out of the Apple ID and back into your own? Alternatively, just give them ur debit/credit card and let them buy the sub. There’s apps that you could use to create one time use payment cards with specified amounts. (Burner cards).
when you say a gift cards 2200 is that like the amount you have to buy it’s not possible to buy or load a gift card with your chosen amount? That’s sort of odd ..🤔 prepaid releoadable debit cards here in the states and many gift cards you just load up with however much you want (+ small fee sometimes for like the card itself… they say) idk perhaps none of this is helpful … if so.. sry.. good luck.