A simple fix would be to cut your red wire into two desired lengths. This will require you to use more terminal connectors, but there should be enough in the KoP to do that. You can also order more 6 awg wire, or find it at your local hardware/electronics store.
You might have 6AWG wire that is already crimped to the Andersen SB50 battery connectors. If that’s the case, then you just need the one Red 6AWG wire to connect between the PDP and main breaker. Then connect the red end of the SB50 connector to the other side of the main breaker and the black end directly to the PDP.
Typically, the robot side battery connector has a red and black wire attached. The black goes to the negative terminal on the PDP, the red to one terminal on the main breaker. Then, a red wire goes from the other port on the main breaker to the positive terminal on the PDP.