How to remotely access transmission on external network?

Hey guys, I just create my first NAS with a RPI3 i already have here, and install the transmission plugin on it.

I set the transmission for remote access and I was able to access it without any problem on my LAN.

But I'd like to access it outside my network too, to add torrents and see the downloads status, but I'm a complete
noobie on it, so I'd appreciate if someone could give me a little help.

So what I tried till now was:

1st: I enabled the port forward on my router for the port "2000" and confirmed it was open.

2nd: I set this port on the transmission plugin

3rd: I create an account and host on NO-IP and set my router to automatically update the IP on it

So I tried to access it on my browser using "NO-IPHost:trasmissionport" but I'm yet unable to connect, the browser just shows the message:

"The connection was reset

The connection to the server was reset while the page was loading."

There's something else I need to do for it to work?

Zitat von gderf

If you are trying to connect to your WAN address (or a hostname that resolves to it) from a LAN host it generally will not work unless your router supports NAT reflection or loopback.

Have you tried from another machine out on the internet?

I've tried on my cellphone through the 4G network, without success.

Okay, I tried to use my external ip directly and add "/trasmission/web" at the end, but no success yet.

Maybe the problem is my port?
That was the only port I was able to open, all the other I tried still shows as closed even after port forward on my router.

EDIT -------------------------------------

Okay guys, I was finally able to make it work, it seems the problem was really the port, my ISP seems to use some kind of firewall who was blocking the ports.
So I call there and ask them to open a port for me, then port forward the port they gave me on the router and it's working like a charm now.

Thanks everyone who helped me.