When we bought the property we now list on Airbnb, insurance was a big concern for us, as We'd heard it could be quite costly, or even unavailable in the case of Short-term rentals and certainly for wildfires, which are a major concern in our part of Northern California.
We called our insurance agent and were able to add it (with an str clause) through State Farm. It's about $1100/year (the same price as our property tax) and we account for that cost in setting our nightly rates.
We already maintained a liability umbrella as I have another business and we feel quite fortunate knowing that major damage that won't be covered by Airbnb can be covered by our insurance.
P.S. We have pet insurance on our dog as well in the case of unforeseeable major accidents. It is curious, however, that where many countries have implemented public programs to address cases of extreme loss, the U.S. turns to the private insurance industry...