Day 2 my thoughts on Cobra II (wifi)

Hi All, I am a complete noob to anything resembling a micro-controller. I have a very basic understanding of electronics so I bought a Cobra 2 and extender and a bunch of modules.
I can build/run code on the mainboard no problems, however after connecting the extender and plugging in a module (in this case the MotorControllerL298 and the LED7C) via the extender, the code runs but nothing happens.
I can plug the LED7C into the mainboard socket, and blink it, yet when I plug it into one of the extender sockets it doesnt even power up.
I have installed a 2032 battery into the extender (although I have no idea why it would need one?)
The extender I just connect with a 40 pin male to male pin row? I have not yet soldered the pins to the mainboard or the extender as it looks to have connectivity to all of the contacts.
The attached image shows how I have connected the extender to he mainboard.
I am at a loss as to how to do much of anything with the mainboard as there is little to no documentation targeted at the cobra 2. All of the documentation I find is targeting other mainboards. The search function on this forum is bad at best :confused:
This is the code I run:

Debug.Print("motor 1 100");
            motorControllerL298.MoveMotorRamp(MotorControllerL298.Motor.Motor1, 100, 1000);
            motorControllerL298.MoveMotorRamp(MotorControllerL298.Motor.Motor2, 100, 1000);
            motorControllerL298.MoveMotorRamp(MotorControllerL298.Motor.Motor1, -100, 1000);
            motorControllerL298.MoveMotorRamp(MotorControllerL298.Motor.Motor2, -100, 1000);
            motorControllerL298.MoveMotorRamp(MotorControllerL298.Motor.Motor1, 0, 1000);
            motorControllerL298.MoveMotorRamp(MotorControllerL298.Motor.Motor2, 0, 1000);


What do I do with the “Serial Mode” contacts? bridge them?
As the only way to connect the MotorControllerL298 is via the extender I need it to work!
On another note, why does the extender have all of those holes in it?
Please help!

the extender board holes are for mounting modules.

the serial mode pads are used when you want to use a serial port for debugging instead of USB.

Thanks andre.m!

thank you both for answering all my questions.
I soldered it up and its working now.