Why is apple asking me to verify my card info when im purchasing a free app

for the past few weeks i haven’t been anle to download anything because everytime. igo to do anything a notification pops up saying verification required, ive berified my card details like 5 times now and everytime it says “To avoid interruptions to your subscriptions and purchases, verify your payment information or add a new payment method.” even though i’ve already verified my card. Apple also tried to take $10 through my wallet a couple of weeks ago even though i didnt have any subscriptions nor had i bought a paid app, and this whole thing started happening after apple attempted and failed to take money from my card as i had barely anything in it. can someone please help as i urgently need this fixed so i can use certain apps for study’s