My codes are not safe while using Github pages, everyone can see my tokens, IDs, etc. please let everyone make there page private without upgrading, or I'm gonna switch to firebase.
I'm not sure what it is you're trying to accomplish. If you're looking for a way to have a private Git repository, unlimited private repositories are now available to free accounts. If you're looking for a way to secure your GitHub Pages website behind a username and password, then there are techniques for doing that kind of thing, but nothing that is built-in to GitHub Pages.
If you can let us know exactly what it is you're trying to do, we can hopefully point you in the right direction.