Form 709 question for student in college using our credit card as an Authorized User

We have a student in school and his COA alowance for off-campus living is pretty small. So, we are helping pay rent and he uses a credit card for food an incidentals. The credit card payment is withdrawn automatically each month from a checking account owned by both parents. For 2021, the total above COA (and therefore not covered by his 529) may exceed the $15,000 gift tax limit above and beyond the COA allowance, so it becomes a gift. The question is, how do you represent these monthly payments on 709 Schedule A? Does each month need a line, or can we group it into one line (“Cash - Education support above COA”)? And I do assume the description of the property would be ”cash”?