It appears the project you have linked to is several years out of date.
I've created a similar but newer and more feature rich LGSM web interface. If you'd like to try mine you can find the link to the GH below.
https://github.com/BlueSquare23/web-lgsm
The installation is similar to the above mentioned project.
1) SSH to your server
2) Clone the web-lgsm repo
3) Run the install.sh script
4) Run the init.sh script to start / stop the web portal
Check out the projects readme for pictures of the setup process and the app in action!