Why doesn't DuckDNS work?

Question

ubuntu

Good day! There is a home server on ubunt to which remote access was required. We have: a gray ip from the provider, the server itself, a router on openwrt, duckdns. the port is forwarded on the router, the port is also allowed in ufw. On Ubuntu itself, I acted according to the instructions for duckdns configs on linux via cron, a log file was created, the answer is "ok", but nothing works.

Answer 1

Dynamic DNS will not give you access from the world to your server... it is only used if there is a "white" IP from the provider, but it changes periodically. And in order not to rebind DNS to IP constantly, such things are put.
If you have a completely "gray" IP from Provo, then such things will not help.
Options
Buy a white IP from Provo
Buy any VPS for a penny and raise a VPN server there. Connect the home router to the VPS as a client, and then go to the VPS IP, which will redirect to the home router