Doorbell won’t go into setup mode

Hi! I've just received a doorbell 2 from my sister, she has deleted it ok her account, but when I try to set it up, I'm not getting the white lights at all after pushing the setup button. I also, cannot see the setup network on my iPhone8 or iPad to allow me to join the network as per the instructions. I've tried the hard reset, but it's still the same. What can I do now?