Simple Load Balancing Failover

I have a simple load balancing setup. I have an origin with one server and when that server is down I want all the traffic for my domain to be routed to the other server.

I setup my Primary Pool my regular server IP

I set up my failover pool with the failover server ip.

However if I power off my primary server, my primary pool goes to critical, but the failover pool doesn’t activate. am I missing a step here?