Update from my side. I made a simple test and created an account at duckdns. This is easy to setup via the router and as it is embedded in the WEB GUI. I have choosen duck DNS because I like ducks....

@Philbert Thank you very much for your answer. But the result is the same no matter where or who is trying to access my DNS Link. I asked several people to access my link out of different networks...

Hi guys, I created a dynamic dns name via tplinkdns.com and binded with my router. The dynamicdomainname seems to work properly. IP address is can be achieved by looking up or pinging the name....