It’s collected in most states and in some countries that have elected the tax to cover short term rentals: (including France, Germany, Switzerland, India, Mexico, Brazil, Italy) https://www.airbnb.com/help/article/653/in-what-areas-is-occ...

Outside of that list, the host may have to collect it themselves if the location is not supported yet: https://www.airbnb.com/help/article/654/what-is-occupancy-ta....

(Disclosure: I work at Airbnb)