Animal Plastics is incredibly busy. Try and call a couple of times and see if you can get someone on the phone.
It is not listed as an option on the webpage for most of the cages, but you should be able to get them to install a ceramic incandescent fixture (or more than one) for an extra charge.
They do allow customization, though it slows the order. I've got one on order with a tall litter dam, and extra holes for lights and probes.
They have bearded dragon cages with incandescent fixtures as a standard option:
https://apcages.com/collections/special ... -24l-x-15hYou can install incandescent fixtures on the underside of the roof of the cage yourself (with screws/bolts). If you install your own fixtures for lights inside,
you should ask AP to drill holes and slots in the roof of the cage for the cords to come out of (the cord comes out of the hole, and fits in the slot on the top of the cage so it exits in the back... this allows you to stack cages).
Keep in mind you will need a space between the fixture and the pvc, as pvc doesn't respond well to heat. AP uses nylon spacers for this. You could use those or similar insulating materials. As an alternative, Arcadia makes a fixture with a bracket:
https://www.reptilebasics.com/dome-ligh ... older-pro/When I ordered mine a few months ago, they quoted me an 8 month wait time, so consider that.
I drew a diagram of the cage and sent it to AP so they could customize it. The diagram shows the position of the heating panel they are installing, two probe holes, and holes for incandescent/flourescent lights.