It looks like Airbnb is beta testing a non-refundable policy uhder the Flexible and Moderate options. You have to check a box for it. The box would show once you slecet one of those 2 cancelation policies. I had a couple of guests booking non-refundable for the 10% discount it provides. One guest is having issues selecting that option, though...she called airbnb about it and they said it’s a technical issue. Hope it’s resolved soon. I personally like to offer non-refundable bookings, especially during busy season.