How to not use local host for auth-server

[RealMCCurtis]

Main Question.

I currently have my spotify api website for getting top artists so you get onto the main page (https://matthewcurtis4.github.io/myapp/) but when you click login it redirects you to my auth-server which works perfectly on my computer but it is a localhost so it does not work on others computers/phones. Does anyone know how I would go about fixing this? Would I have to create another github project with the auth-server app and redirect it to that website or is there an easier way of doing it.

Heres my github any and all help appreciated! 

https://github.com/MatthewCurtis4/myapp

I have it working fine through github and it loads the website ( https://matthewcurtis4.github.io/myapp/ ) and here is my github (https://github.com/MatthewCurtis4/myapp). To get the app working I did not include the auth part in that github so it would not mess up the path but when the auth-server is called it calls to a local server so it goes to localhost:8000 and can not load obviously since it is a local host.