2017 Subaru Impreza Premium head unit amp

I have managed to pull the head unit and am trying to add a jbl 4 channel amplifier. This model 2017 Subaru Impreza Premium with 6.5" display has 6 speakers. I have replaced the 4 door speakers and will likely also replace the dash speakers. The back of the head unit has 10 ports. I get a variety of responses when I disconnect certain ports. I cannot figure out which are the remote power and speaker line level wires. I would be happy if someone could enlighten me as to which ports had the wires and perhaps even which wires to connect the amp to. I have installed amps in previous vehicles, but this one has so many wires in the back. Also, I hooked the ÷ amp wire to the battery, grounded the amp, and connected the remote to the thicker blue wire in what I think is the main stereo harness but the amp does not turn on.