nat port

Hey everyone, currently, I am struggling with opening some ports to the internet. My setup is: - ISP modem with DHCP enabled (ISP ensured me that the ports should be open here) - Aliexpress box with PVE and some VMs. - One of the VMs is acting as my main router/DHCP server/firewall (OPNsense)...

I want to use computer in LAN connect all VM in proxmox using IP_LAN: PORT. I have no experience in networking.