RT-AC87U - ddns issue

[pemahy]

Hi all,
I have DDNS issue on my Asus RT-AC87U router.
I'm using ASUS DDNS service.
I can connect via DDNS service through IOS APP however I can't connect using the same address through the website so I can't manage my router remotely. I'm getting message that specified site is unreachable.
Does anyone can help to point to the resolution?
Thank You

 

[RMerlin]

Don't expose your webui to the WAN. It's an invitation to hackers to come compromise your entire LAN.

Use a VPN or SSH tunnel if you really need remote access to your router.