Why won't my app allow me to use keypad functions?

I just installed my SS and downloaded the app. On the app, all I can do is monitor my camera. It won't let me access keypad functions. I didn't purchase a plan because I read that SS is the best system to use without a subscription.

Also, I have Google Nest in my house and tried to connect SS but it says I have no compatible SS account.

Do I need a subscription for SS to access all the functions of the app and connect it to Google Nest?