How can can I get my Go Power 120v kit to charge my battery power generator?

Fasttimes

First post so I hope my questions aren't obvious. I have a GP 120V solar kit that I'm trying to use to charge a 300watt portable lithium battery generator. The solar kit has a controller that terminates out with an anderson connector. Generally connected to that is a pair of battery clips.

The battery generator's sole input is a 19v DC plug. They supplied adapters for MC4, 12v cigarette plug, and 120v house all to the DC plug. So I sought out a connector that might work and got an anderson to MC4 adapter. I then connected the MC4 to DC plug adapter and into the battery box. And no dice.

Issue I see is that the solar panel controller must get power from the connected source to turn on and provide the solar generated power. But when connected to the battery generator it got nothing thus did not turn on.

Questions I have are is there some way to fool the solar controller, or some other way to get this to work? Is there something obvious that I'm missing? Appreciate the feecback.