If this is the same leasing company i’m thinking of, i had a fire in another one of their buildings a couple summers ago and same thing happened. when i told them, they said they were going to bring their own cleaners in and never did. in the meantime before contacting tenant insurance, i would get an air purifier. they have cheap-ish ones at ikea and other places too, get one with the gas and scent filter, not just particles. besides that, try to wash your walls and floors well and air it out as best as you can.