Reported on Reddit:

Hello, i am having a hardtime finding how to complete the 2nd quest of the robot. I did it twice with my friend and we managed to deal with a miniboss who gave us a piece of paper saying "usage of force by a pretorian not required" and then nothing happened, so we though maybe someone "not a robot" had to kill him so usage of force would be required by a pretorian" but it didnt work either. It might be a translation error since i play in french but if you could give me a hint it would be nice of you :)