assuming that your wan interface is ETH03 , and the dvr is 192.168.10.2 , and is listening on 80 tcp try this
and from the internet , type your.fqdn:8082
I tried this one but didn’t work. I am using 3 WAN connections. The static IP is on Eth3 (relates to ppp2) so I tired all the options e.g – Eth3, PPP2 and ANY as input interface but it’s not working. Still error – page not found and if I don’t specify the port in web address it goes to Zeroshell login page.