[RodinMe]

Have you been using a LAN IP address of your Kodi box?  If you're running Kodi on a wireless or other home network, you must use the WAN IP address of your network router.  If you don't have a fixed IP address issued by your ISP, you'll need to use one of the DDNS services that will issue you a DNS name, translate it to your WAN IP address, and help to keep up the IP address if and when it changes.  You'll need to sign up for the service.  Your router will likely help you to manage the service - enter the DDNS login information, track and report any changes to the WAN IP address so that the DDNS service can issue changes to Internet DNS servers.  Finally, with a router you'll need to set up port forwarding so that the router knows how to send Kodi traffic to Kodi.  I suppose that you'll actually need 2 ports forwarded, one for Kodi (8080 usually) and another one to point to your OwnCloud app.

Your web server must also support (Python 2.7, not 3, I think) apps, and must have the libraries listed in the requirements.txt file installed.  I would assume that Python would be installed since you say you have WSIG running.  If not, you can download and install python, from python.org if you use as Windows or OSX box.  I suspect that most Linux boxes include python in the default distribution.
.  If and when Python is installed, you can use pip to check the libraries and install them if needed.  The command "pip install -r [Path to]requirements.txt" should tell you.