the 188.8.131.52 is GoDaddy's forwarding IP - this would mean when you setup the DNS settings in GoDaddy, you put in the IP in the lower right corner for DNS
This is forwarding to 184.108.40.206 (Your Public IP Address)
which in turn is trying to load 192.168.1.3 (The internal IP of your QNAP)
WordPress is not a server - you need to run Apache or Windows IIS or something of the sort.
So the domain "may" work inside your network, but if you want the public to get to your domain, you will need to get help from someone that can do network configuration as you more than likely will need to adjust your router / modem to pass the traffic correctly.
Additionally while the files may live on your QNAP device, your local computer may actually be the web server
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