There are different Fritzbox devices with different ways to configure DDNS. Typically, you’ll just need to enter this information:

DDNS Provider: No-IP
Username: Your DDNS Key Username / Email
Password: Your DDNS Key Password
Hostname/Domain: all.ddnskey.com
Server/Server Address: dynupdate.no-ip.com
Not every device will ask you for a server or server address. The service will still work without issue, if the device does not ask for it.

DDNS Key usernames and passwords are created individually for each hostname or group of hostnames. They are generated from the DNS Records page in your account.

However, some firmwares will require an update URL using our API in order to set up DDNS. Here’s that URL:

https://dynupdate.no-ip.com/nic/update?hostname=<domain>&myip=<ipaddr>,<ip6addr>

You’ll put in that URL exactly as is shown above, the Fritzbox device should add the No-IP account information you entered in the other fields into those placeholders.

In case your Fritzbox configuration is different or you need more in depth information, you can always check their knowledge base directly.