Hi @Marwin0, I'm not certain I understand your question. I think you're saying that the guest cancelled within 1 hour of booking? Is that correct? Or within 1 hour of the reservation? Also, I'm not sure I understand why you are only refunding her 2 out of the 3 nights...
You have a moderate cancellation policy, which means the guest will be AUTOMATICALLY refunded the full fee within the first 48 hours of booking - YOU DON'T NEED TO DO ANYTHING - Airbnb will automatically do it for you. They will also be refunded the full 3 nights. If they are within 5 days of their booking, they will not be refunded for the first night, but they will be refunded 50% of the accommodation fees for the remaining nights. Again, this will be applied automatically - just let the guest know that Airbnb will send them the money.
However, if the guest has already arrived (this is where I'm a bit confused) and wants to leave early, then they will not be refunded the first night, but 50% of the accommodation fees for the nights not spent 24 hours after the cancellation occurs are refunded. Again, this will occur automatically.
See here: https://www.airbnb.com.au/home/cancellation_policies#moderate
If the guest has already arrived and wants to leave early, and you want to refund her 100% of the accommodation fees for the remaining nights, then you will need to do this through the resolution centre. But just wait and find out first what refund they have got from Airbnb before you go ahead with this as you might find that they end up with more than they paid in the first place!