OE is from the factory. Factory Accessories are from the OEM. Aftermarket is something a 3rd party produces. Think of OE as the roof rack that came with the van, a Factory Accessory is the Mopar rack you buy from the dealer if your van didn't come with one, and Aftermarket is the rack that Yakima sells.
The gadget you bought comes with a cable that is meant to connect to an aftermarket remote start (I linked to their product page that says it). Which you do not have.
The module in the stock Pacifica that is my guess (there are 4 modules involved, the RF hub is simply the first in line), is an actual different part depending on whether or not you have a remote start. Think of the assembly line where there's some UAW guy standing between 2 boxes. One has RF hubs for vans with remote starts and one has RF hubs for vans without. He checks the build sheet of each frame coming along and reaches into the appropriate box for that van's hub. Now, I don't know how different they are, and I don't even know if the RF hub is where this gadget you bought would want to plug in to. But the Mopar accessory remote start kit comes with an RF hub to replace the one your van came with, so it's a good bet that your RF hub isn't going to play nice with your DroneMobile.
Try contacting DroneMobile and asking if they can make a guess, or if they can recommend an aftermarket remote starter. If they recommend one, get it. If they tell you they don't know of one, print out that email and take it to Best Buy so you can return it and get your money back.