Cannot open the case of ring 4 battery doorbell

I may be missing something obvious, but I have recently bought a battery powered ring doorbell 4 and I have no idea how to open the case so I can charge the battery for the first time. There is what looks like an orange piece of plastic inside the hole where the security screw would go. I can't open it by squeezing the sides or sliding it off from the bottom either. Does anyone know what I need to do so I can install my doorbell?