Lock/unlock signal to rear doors - 2016 double Cab

I have an Alu Cab Alu-Cabin on the back of my 2016 double cab tundra. I purchased a used electronic lock for the Alu Cab for the back door that is made by 813 Fabrications. This electronic lock automatically actuates a bolt lock when I use the key fob to lock/unlock the doors of the vehicle. After speaking with 813 they said that I need to run a wire back to one of the back doors and find the Unlock/lock signal that tells the door lock actuator to lock and unlock. Hoping someone has an Electrical Wiring diagram that might be able to help me determine which wire I am looking for.

Any help would be appreciated.

 

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I would consider connector behind B pillar....OP1 pin 20 Grey for Lock and pin 21 for UnLock.

 

Holy hell!!! Wow truly appreciate the detailed response and good to know the EWD’s are available when I need one. I’ve been looking on EBay to buy the factory repair manuals and EWD’s and they just seem to be available like they are for my Lexus LX470.