My kid is obsessed with Roblox gift cards and it’s driving me nuts

Every time we go to the store, my kid immediately spots the Roblox gift cards at checkout like it’s some kind of sixth sense. Doesn’t matter if I tell them we’re only here for groceries they’re already plotting how to get Robux out of me. They’ll beg infront of everyone and it looks so embarrassing just to get $10 worth of card. Anyone figured out how to break the Roblox gift card madness?