Don't expect any refund if your plans have to change!
I booked for 7 days but had to leave after 2 days for personal reasons, I asked for the standard 3 day refund but the host replied this:
"Look, your request is no longer active as I wrote you before.
In addition, it is really difficult for me to refund a guest without valid reasons, i.e. health or Covid.
I am unable to refund guests who are mistaken about their travel arrangements. It was up to you to only book 2 or 3 days, even if it means extending your stay, but not to rent for a week and only staying for 3 days...how do I rent your room again?
in short, it's not up to me to pay for your family issues, I have a lot too."
I felt it was fair to ask for the small refund but clearly the host did not.