First time port-forwarding

Hey!

So I’ve been trying to port forward 25565 and I’ve tried everything that I’ve been told. I could of messed up somewhere or something but I’m pretty sure I’ve done it. Whenever I check online port checkers or ones that I download myself it says that the port is closed or it failed. If there are any screenshots i need to attach then let me know.
I’ve been going at this for the past week and cant figure anything out. Any help would be appreciated, thank you very much!

Post your config
/export hide-sensitive file=anynameyouwish

Also are only external users using your servers?
If you have internal users are they accessing the server via its LANIP or the public IP (loopback).