Unfortunately, we had no chance to meet O. in person. Our communication with her was via another app rather than Airbnb app and that what I couldn't find any explanation for.
The place was just okay to sleep and use the bathroom. My cousin and I were sharing the apartment with someone else, and our lock of room's door was broken so, we felt unsecured. Fortunately, nothing bad happened as far as we know.
Above all the rules of what to use or not were not so clear for me.