Good morning @Thor6
Here are the steps:
==>Menu
==>In Listing details choose
==>Guest safety
Here you can tick the two boxes for babies under 2 not welcome and the 2-12 not welcome. You should indicate to the parents why your listing is not suitable and unsafe so that they understand why you have chosen not to include them.
However, if parents still want to bring their kids along, there isn't very much you can do about this as this might well be considered as discrimination by parents even with the boxes ticked.
I have the same restrictions and always ask with my guest who is coming on their trip as I explain that I have age restrictions. I also indicate this in my house rules on my listing and send this again just after a reservation in case they didn't see/read the house rules when they decided to book.
All the best
Joëlle