@Lisbeth47 You don't need to do anything. You didn't "lose" anything if you were paid for the booking. It's not your problem that the guest didn't show up.
So the guest didn't cancel? Was this a long reservation? Have you communicated with them to see why they didn't show up? Did you communicate with them before check-in day to get an idea of when they'd be arriving? If it's a long reservation, sometimes a guest might show up a day late for some reason, but they should communicate with you to let you know.
Do be aware, though, that the guest may ask Airbnb for a refund, and if Airbnb gives it to them, they will deduct the amount of the refund from your future payouts. In that case, the dates they booked should open up on their own, ad if they don't, you'll have to contact customer service.