Setting up previously owned ring alarm system

Hi all, I bought a house with a ring alarm and ring cameras system installed. The previous owner dissociated those from their account. I have been able to set up the ring base station on my WiFi network. This automatically tries to connect to a keypad, contact sensor and motion sensor. However these don’t connect. Following the instructions on the ring app when connecting the base station, it says pull the tabs, which I can’t do as they are already installed. I tried the obvious, unplugging or removing the batteries. But they don’t ever connect. In the devices section of the the app, it lists the items as “waiting to connect to network”. I’ve tried removing them from here and reading using the qrcode of the 5 digit code, still no luck. What do I do?