I don't understand what this is asking, the usb cable is the power lead? There is only one cable that goes in which is the usb c one.
Surely if there is only one that comes with it you can use it? Why would you need to buy a power cable separately? I have the older nest iq outdoors and it's just USB c to USB c but with a fancy weather proof shield on one end so it can be locked into the camera.