What FOSS reverse-proxy to use in a redundant configuration?

Hi, I was looking at different reverse proxies (Traefik, Caddy, NGINX, Apache (mod_proxy), HAProxy) - I wanted to run two instances of a proxy on different devices for failover. I do not find much about running reverse-proxies in a failover configuration, could someone point me at a resource related to these proxies so I can figure out how to run reverse-proxies in an HA configuration?

Thanks