@Rene1655
Go to "Pricing", click on "Length of stay discounts" and add a monthly discount you are comfortable with.
You offer a 12% discount for weekly bookings, perhaps do a 20% or 25% discount for monthly. Check out listings near you to see what they do.
When the guest books, Airbnb will take the 1st month upfront, pay you the 1st month after check in and then charge the guest monthly and pay you monthly.
You would also have to release the dates to be booked, at the moment you only have 6 weeks available