Hello Meowmeow
1 - Download GB to your VPS, be it Windows or Linux
2 - Extract the files
3 - Run gunthy-gui-xxx. It will point to localhost:5000 <- do not consider it
4 - Instead, in your browser in your local computer, use the IP you use to reach your VPS, like 123.124.125.126:5000
It should open the Gui and prompt you to create a password.
Also make sure that gunthy-gui, in case of running in windows, is allowed in the wifi networks you regularly use.
If it doesn't help, send us a screenshot with the error,but I'm sure it will work
Best regards