Work backwards from the month you want. Give it a payout target, the occupancy you expect and your fees, and it returns the average nightly rate those three imply.
The maths is one line: the rate you need is your payout target, grossed up for the platform's cut, divided by the nights you actually expect to sell. Everything else on this page is that line with its assumptions made visible.
Two traps worth naming. Chasing a monthly target with one flat rate leaves money on the nights your city fills and empties the nights it does not — see seasonal pricing. And if the occupancy you typed in is the number you wish you had, run it through the occupancy calculator from your own calendar first.