It depends on the router.
Some routers isn't on www.portforward.com and then you have to go searching for them.
What I do usually is I go out and check what my router is called and then when I search it on google I write:
"<Internet provider> <Router name> portforwarding."
That works in my case at least, cause my internet provider had an support site, which showed how to portforward my specifically router.
But anyways check if your router is on www.portforward.com and if not try my suggestion, it might work for you