Airline Credit/ Bag Fees/ RACI????

[natter]

Have an airline (AT) credit that I was wanting to use for bag fees, question is, how does this work with RACI? Am I correct in thinking you would need to deal with the airline directly because it is a credit, and not call the regular BAGS# when paying for bag fees? Would the RACI people call the airline to set this up or would I have to check our bags at the airport ourselves?

TIA