Bad address means that your router cannot resolve our server's name (www.hotspotsystem.com).
Be sure that the router is connected to the internet properly. You can also check the DNS settings of the router before you run the setup script.
You can try to log in to the router via console/terminal and try
This means the router couldn't resolve the name. You can try an IP address:
root@OpenWrt:~# ping 188.8.131.52
PING 184.108.40.206 (220.127.116.11): 56 data bytes
ping: sendto: Network is unreachable
This means there is no network in the router. You should have an internet connection in the router to make the script work. (Connect the router's WAN port to the internet)
If it could ping the IP address, then it means the problem is only the DNS setting, you should enter a working DNS server, for example google's 18.104.22.168