The jungle is easy to pack for if you ignore the safari-catalogue look. You need to stay cool, keep insects off, and be able to sit quietly in a canoe for an hour.
Clothes
Long, light trousers and long-sleeved shirts in green, khaki or grey. White and bright colours spook animals; black attracts insects and heat.
Everything else
Binoculars, a 35+ sunscreen, repellent with DEET, and a dry bag if you want your phone to survive the canoe. Leave the drone at the hotel; the park doesn't allow them.