Can you save the database to Github

Create a private repository in Github with a fixed name and access it with Auth0. Upload the password database to the repository.

I have also recently been thinking about creating an open source password tool with Flutter. Found that there is already an AuthPass. So I gave up.
My idea was to store passwords encrypted in clear text on Github or GoogeDrive or OneDrive. Save the user’s Settings as well, Log in using one account from multiple platforms Automatically synchronize user Settings and passwords.

No, not right now. But it would be fairly easy to add support for another storage solution… You basically have to implement CloudStorageProvider: You could take a look how the other backends work, e.g. WebDAV:

There is already support for google drive and one drive…

Although I personally do not really see the benefit of using Git(Hub) to store passwords…

Maybe I didn’t make myself clear。
If I am making this application, my process : Log in (oneDrive,GoogleDrive) → Create local Repository → Create cloud repository → Local and cloud real-time synchronization. This ensures that if a user forgets to upload to the cloud, the cloud data is the same on other platforms. Otherwise, I have to import the database every time. Or download it from the cloud.
The only nice thing about GitHub is that there is no limit to the size of the repository. I can use an open platform to store any number of files in my private repository

I will try to study this CloudStorageProvider.

I have no idea what you are talking about… making what application?