DynDNS by D-Link. Does anyone use?

Question

Domain Name System

DFL-260E .
I still don't understand the terms of the (free?) DDNS service from D-Link . Let's say I register, enter the MAC address of the device and its serial number. But then I'm told about some vague regular Update .
What they mean by that - I have no idea. Either the activity of the host, or my manual periodic climbing into the account and pressing the pedal: "Yes, I'm still alive!"
It's about a free service. As far as I understand, it is provided to registered D-Link customers/devices, with some restrictions.
Or have I misunderstood everything?

Answer 1

It's about updating the client application (Dyn Updater App). It must be installed on the host, there are versions for Windows, Linux and Mac. After installing the client, you don’t need to update anything, it does everything by itself.

Answer 2

Does this mean that if I do all this on a device where it already exists (in this case, on the DFL-260E firewall), no problems are foreseen in the future?