Idatalink ADS-THR-NI5 Harness Question

I plan to have a Compustar CSX4905S-KIT (CM-DC3) and Idatalink ADS-THR-NI5 installed on my 2019 Infiniti Q70L PTS. All the cross referencing I have done states that this starter system and harness are compatible  with each other. I will have this project professionally installed. Issue that I ran across is with the  harness. At first glance, I noticed this harness does have the big black square plug that goes into the M1 port. My understanding is the is the main power port that connects ignition. I am not sure what else I am missing to facilitate the install. I want to have all parts on hand when I show up for my install. Any advice regarding this issue would be appreciated. By the way I have matched all other connectors to thier appropriate port on the CM-DC3 and harness. M1 is the issue.