Multi wan with clustered configuration

[unam]

Hi,

I want to setup a ha cluster with two of my physical firewalls. I was reading the differents docs but no one of them seems to solve my problem.

I have two opnsense with a wan connection. They have a lan interface connected to a switch and every of their wan interface is connected to a dedicated fibre link.

In your opinion, what are the docs, and how do I  can make a ha cluster with failover and loadbalancing.
Every docs talks about multiwan with one firewall or ha with two firewalls but one connection.

I just attached a picture of my setup.

Thanks for your advices.