Why am I getting "A data breach on a site or app exposed your password. Chrome recommends changing your password on "SITENAME" now."
The code appears okay. If you are using Google Chrome it has a feature that warns if the password you are using has been previously compromised. So, if you are testing with a common password this may occur. If this is production than you should update your password as the warning indicates.
this a new feature from Google Chrome to check password compromised, you can read more about on this Google article: https://security.googleblog.com/2019/12/better-password-protections-in-chrome.html
They also have this Beta API: https://cloud.google.com/recaptcha-enterprise/docs/check-passwordswith that, we can check directly if the user/password is compromised instead to depends on Chrome to inform that as a warning to the users/ customers.
I had the same problem in an app build in react in a development environment in vercel, I solved by changing the password to a more complex and secure one. That is, it has nothing to do with your app