@Zdenek2
if you are advertized for 5 guests then booking can't be made for more guests.
If you can host for example 8 guests then you have to advertize for 8 guests. You can set your price for 2 guests and then charge every additional guest after 2
As booking is already made and charged you can now request additional money through the resolution center (send or receive money) or change the price (change reservation) but they have to accept it.
If they refuse or ignore it then you don't have to let them inside as they showed up with more people then booked.