why do you need to login when working on the project locally, if you're working on your project locally, then you are using a local enviroment, and a local database.
what you do then is you push your website to a server, the website on the server will function the same as on your local system, but others can access it. this is done by
local -> push -> github
server <- pull <- github
If you want to update your website, you just do the same thing.
If you want to login to the admin on server side, you will login to your host dashboard, here you can use the file manager to upload your project.
any kind of admin on the website is usally just to delete or update stuff in the data base, but if you cannot be bothered to make a admin dashboard, you can always just run SQL commands depending on your DB type.