Fitting Ring Video Doorbell Pro

Hi. I'm installing a Ring Video Doorbell Pro and I have a question about the height of the doorbell button. The height above ground needs to be 120cm, however, my front door is down a slope and then some steps, so the horizontal line from the doorbell hits the street at ground level. The fitting advice talks about doors which are up some steps, but not about doors which are down a slope/steps. https://support.ring.com/hc/en-gb/articles/115002582386-Using-a-Wedge-Kit-to-Properly-Position-your-Ring-Video-Doorbell-Pro Do I need to raise the button/camera a bit (120cm seems low anyway) or does it need a wedge kit? Thanks, Charlie