Point to Point Fiber Connection via Balance 20

We recently switched to a Private EICA Circuit and EPL circuit. Attached is the basic setup. My question is how do I get the the two office lans to connect and talk. I can ping between PC’s from HQ to remote with a direct connection to and from a laptop using and

We eventually want to share the HQ internet connection and and leave the internet connection at the remote office as a backup. How do i set this up between my Balance 20.

The remote office really only needs access to the NAS data servers. Everything else we run for apps is cloud based.