https://github.com/joshwnj/json-mode/blob/0e819e519ae17a2686e0881c4ca51fa873fa9b83/json-mode.el#L140
This command is bound to C-c P, which is a C-c letter keybinding, reserved for user customization. It should be replaced with some other binding, such as C-c C-w, which doesn't seem to be used by the parent mode. I can submit a patch, but deciding on what keybinding makes sense first is the more productive way to accomplish this.