Maybe we should clarify a bit...
...so that the locally stored website is accesible via the www...
There are two ways to achieve this!
- One is the mentioned "Free DNS/domain" setting in the Superglue admin panel (Superglue as your primary router).
- The other one is with using your existing local network router (where your internet comes from at the moment...), and then the Superglue device is a network client like your laptop or your network printer.
--> Only if you want to use Superglue as your only router (and get rid of your old router), then the "Free DNS/domain" settings are relevant to you...
(But I suspect this case is less common. For example in Germany, ISPs usually provide a router with an integrated DSL modem. If you want to get rid of this, you would need an additional DSL modem)
Otherwise you will configure your old router, to forward incoming http requests to the Superglue device inside your local network.
If you want to (or have to) integrate in your existing network, you ignore "FreeDNS/Domain" settings and instead you use the first block of options ("Internet connection") in the http://superglue.local/admin panel. follow this path:
connect the device to your existing network via ethernet cable/WiFi
Assign it a static IP (instead of dynamically/DHCP)... The values depend on your network/router and how-to is general TCP/IP network set-up knowledge (we will work on a tutorial, but please use also the vast resources found on this subject everywhere).
For example, your good old router sits on IP 192.168.178.1 with subnet mask 255.255.255.0 and is using the range x.x.x.20 to x.x.x.200 for its DHCP clients. Then you could assign your Superglue device the static IP 192.168.178.10 (outside that dhcp range, but in subnet mask!). Then configure its gateway to the router, hence 192.168.178.1.
The DNS-Server can be whatever you like, e.g. 188.8.131.52 (CCCBerlin).
Then go to your routers configuration panel (see your router's manual) and enable port forwarding and/or Dynamic DNS and see that traffic coming to port 80 (which is the http port) is being forwarded to the Superglue device, in our example 192.168.178.10.
In conclusion: it depends, if you want to use Superglue as your primary network router, or if you just want to integrate it in your home (or organization's) network...
(@DanjaVasiliev I suspect most people want to or have to do the later. At least as starters. So we should account for this)