@Joy-And-Alan0You can message the guests to advise, but you can't retrospectively alter the agreed cleaning fee at the time they booked. You would have to give them the option of cancelling the booking without penalty if they chose not to pay the extra (or else Airbnb will refund them if you don't). When a guest books, it's a contract to supply a service at an agreed price. If they agree, you would have send a request for money to the guest to cover the extra.
But you raise a good point given the recent increase in cleaning requirements in the US and what to do about existing bookings that haven't already cancelled. Something to call Airbnb about I would think, to ask them what the policy is.