ORBI RBK20W

I have an Orbi RBK20W mesh system. I bought it three years ago. I would like to purchase another Orbi wall plug satellite. It seems Orbi is making that product anymore and I don't want to buy a used model on Amazon. What can I do? I am not sure. We just want to extend the WiFi. The Netgear website sends you to Amazon. I want to buy a new orbi satellite which works with my current Orbi system. Netgear is not very helpful.