How do I send/request resources from the AI ally?

Based on my experience, you can’t directly force it to give you something (I checked in the disassembler). But the AI seems to monitor all resources. I’ve often noticed that when there’s a shortage of a particular resource, depending on the settings, the map, and the resources it has, it sends exactly what’s missing or what it deems necessary.
P.S.: You could reverse engineer/modify a patch to make it do what you want, but IMO, that’s not necessary.