I’m trying to purchase storage for iCloud but for some reason having a difficult time with my debit card

Are you getting any error messages or notifications? Try - Change, add, or remove Apple ID payment methods - Apple Support.

I've asked the hosts to immediately remove the image you provided as it displayed sensitive credit/debit card information. It is questionable how many individuals may have seen that image so I urge you to immediately call your banking institution and cancel the card.