@Vaneet0 How much to charge would totally depend on how far you are from the airport and how much a taxi would cost by comparison. Maybe charge 50-60% of what an Uber or cab would cost? Also, as Anna said, it might be better not to state it in your listing, but to let guests know when they book that it's available for $XX should they want it. That way, if for some reason you aren't able to do a pick-up (car's at the mechanic's, you're busy with something else), you won't have guests complaining that something that was offered in your ad wasn't provided.
Or state in your listing that it may be available for $XX by pre-arrangement with the host.