Substance to Arnold - Ambient Occlusion

PandaLog

I made a character bit by bit over the summer and want to finish it completely next week.

I painted his Ambient Occlusion map to fake a deeper mouth (substance painter), but I can't find a solution anywhere as to where to plug it in Maya.

Using the aiAmbientOcclusion shader and a mixer didn't work, I'm not sure if I plugged it all in right though, there aren't any visual tutorials or screenshots.

I've been trying anything and everything for an hour, there's no AO option to replace with a file image like in Color or Roughness, or any other properties.

Thank you in advance for any help!