@Jennifer4418 I put Pet information in the very first paragraph of my listing.
"Up to 2 pets, $$$ pet fee per stay".
If you have a type or size maximum, add that in the same sentence.
"Up to 2 dogs, no cats, 50 lb. per dog maximum, $$$ Pet fee per stay."
I note that it is per stay as the AirBnB programmers have not set up the pet fee to be per pet or per night. You can only charge a flat fee per booking. I did research kennel charges in my area, so I know that my pet fee is reasonable.
Additional locations are the House Rules, in my response letter to guests -- "Your request for arrival date to departure date for 4 adults, no children and 2 dogs has been added to our calendar" blah, blah.... and again in my Welcome Package.