You don’t need, nor want, an L-shaped connector. The connector supplied is part of the waterproofing system, so please don’t replace it.
You just need a commonly-available USB-Type-A-Female to USB-Type-A-Male cable. I’d try to limit that cable length to no more than 20 feet to avoid dropping the voltage to the camera too far.
But running a 120V extension cord is even better, if that cord is protected from the elements (no voltage drop).