You can't do it manually, and the owner's manual (page 279 in the 2018 U.S. version) is pretty explicit about not putting a child seat in the front seat. While the light weight of the child seat and child might turn the airbag off via the weight sensor, I wouldn't trust it with my kiddo.
Sorry to resurrect old thread.
Im in the same boat. My backseat is removed. Id like to use child seat in front passenger seat and disable passenger airbag manually. If dash lights up im ok with that when disabled.
Id rather not pull a fuse and disable both airbags but id be willing and to do so. My rational is that i only use jeep on local drives and rarely go highway speed. Airbag to child seat likely to do more damage then me not having airbag in low speed accident. I have another car with a backseat and airbags and better gas mileage for long distance driving.