Hi Team!

Im trying to setup an FTP to access to my files from internet, but i have the following situation.  I don't receive directly from my WISP a public IP because there is a NAT before my router. The case is that when i check on my public IP or DDNS by TP-Link, the IP is different from what my WISP told me it is. I didnt belive them (hahaha) until i could make work the VPN Server using OpenVPN with the public IP they told me to.

So now i want to access to my disc using the public IP and the extra port not being used for the VPN they open for me, but i dont find a way to put as address the public one they told me. Instead it apears the private IP from WISP or DDNS which led me to a public IP which is not correct.

Question is, How can i put manually the public IP my WISP told me to use in Internet FTP option in the router setup and if i really need to put the public IP there or anything else going on.

Thanks and regards, 

Fabricio