You can recycle the old brake cable for this.

Insert the end of the brake cable with a "nub" into the slot on the rear left brake.

Slide the cable onto the slot on the connector.

Slide the other end of the cable into the holder on the right rear brake.

Pull the cable to clamp down the brakes so they almost touch the rim of the wheel.

Tighten the screw so the cable does not come loose.