Can't create backend files, button disactivated with note "dev mode has been started in read-only mode"

Question:
I cannot create any type of backend file in Wix Editor. I use the app in Turkish so the notification I am getting is “Geliştirici Modu salt okunur olarak açıldı” which roughly translates to “dev mode has been started in read-only mode”

Product:
Wix Editor

What are you trying to achieve:
I am trying to create a backend file

What have you already tried:
I have tried to do it in both Local mode and normal Wix Editor mode.

Are you using GitHub with this?

Hello Noah, thank you for your response.

Normally I do use GitHub, but I also tried to create a backend file from the online editor. Both didn’t work.

Edit: The answer is yes. And now I realize that makes changes. Where can I find out about how to use backend functionality along with GitHub?