Port Forwarding Problem

Hello everyone!
I have a problem with Port Forwarding.
Im trying to make a Gmod server to play with my friends but I can figure out how to port forward. I’ve never done something like that.
Also, my port forward options are a bit defferent than in the most of the tutorials on the internet, can someone help me with this?

EDIT: I dont have an option to set the Protocol, I can only add:
IP Address
Internal Port
External Port
Remote IP Address

What did you put in the fields?

Thanks for your response!

IP Address <-- My Ipv4
Internal Port <-- 27015
External Port <-- 27015
Remote IP Address <-- My WAN Ip ( I Tried also to leave it blank)
Comment <-- Its just a name so I wrote “Garry’s mod”

I tried few combination of these but any of them worked

Do you have firewall enabled?

No, I disabled my Windows firewall

Wrong link

I looked up for my router (Totolink n300rt) before and there is no information about it on the site

Um try restarting your router after portforwarding and see if that works. Not really sure how to help you i mean every router is different
Best of luck to you.

Okay I’ll try that, anyway thanks for your help