OPENVPN with Double Nat

[buivietha]

Hi everyone,

i want to deploy and configure OPENVPN follow this topology, but i dont know how

could anyone help me solve this ?

Thank you.
i have forwarding port on modem is 44444 to interface wan Pfsense
what is next step i have to do ?
i want pc1 can connect pc2

[phil.davis]

On pfSense WAN you just need to setup an OpenVPN Remote Access server (probably want (SSL/TLS + User Auth)) with local port 44444.
Add a firewall rule on WAN to pass any traffic to port 44444 - you can limit the source IP addresses if you have any idea what public IP address/es the incoming connects wil come from.
If the public IP that is forwarded in to pfSense WAN is dynamic then you need to use a dynamic DNS provider and set that up also in pfSense so that it keeps a public name pointing at your current public IP address.
Then install OpenVPN client on the remote PC…