Dual Wan Failover No Load Balancing

Hi Everyone
I have a router at Site a with ip of 192.168.1.x and the router has ip 192.168.1.1. It has two wan connections to Site b. Site b has ip of 192.168.2.x and the router has ip of 192.168.2.1. I want to route between the two sites using the wan links. I don’t want load balancing just automatic fail over. The wan links can have any ip address I choose. I have read the documentation, but I am still confused. Any simple way to do this setup?

Thanks
Steve