Advice on mounting using spotlight cam hardwire converter kit

Hello, I'm trying to get my spotlight cam hardwired to several locations on my siding that been pre-wired during construction for power. I purchased the wired spotlight camera and the hardwire converter kit for this purpose: https://ring.com/products/spotlight-cam-hardwire-converter-kit However, although the kit comes with 3 different mounting plates, none of them fit my circular wiring box. The screw holes just don't line up. To mount, it looks like I would end up screwing into the siding instead of the wiring box (bottom right of the pic below)  Any advice for this situation?