Only the ranger stations at Santa María de Pittier and Altamira have camping facilities (per person US$6). There's also a basic hostel at the base of Cerro Kamuk (per person US$6). All of these accommodations offer drinking water and toilets, and – in the case of Altamira – electricity. All food and supplies must be packed in and out.
Try removing some filters. Alternatively, there are some nearby lodgings with availability below.