I do have an IPv4, but my ISP prefers IPv6 and only works with that.
What happens is, i cant open IPv4 ports, because my ISP doensnt provide me with an UNIQUE IPv4, since there arent anymore numbers left to distribute and IPv6 should take over.
I tried putting my IPv6 as the IP number for the server and it didnt work.
Don't use NO-IP to, use DYNU, there you can use your IPV6 Adress and players will not have problem to acess your server. I'm using it, and is working well.
BUT, always a BUT, ONLY people who have IPV6 will be able to connect in your server, who still have the old IPV4 wont.
I will be coolest, i'll give you the step by step how to do it:
1° open CMD (Windows+R) and type ipconfig;
2° get your IPV6 adress as show in the img:
3° open your modem page and get your IPV4 adress, the one that the ISP don't let you open ports:
4° go to dynu.com create an account, and create a DDNS as I did:
Doing that, and opening the ports as you always did with IPV4 should work.
OH, I forgot, in your config.lua, you should use the IPV4 adress, as usual.