Where is my remote git repository password stored on the local machine?

In my case git config credential.helper was empty (local and global both). Turns out the credentials were stored in KWallet. Those are found in KWalletManager under ksshaskpass (even though I am using HTTPS auth for this particular repo) under "Passwords".

if $ git config credential.helper returns manager, the password is stored in the windows credential manager, if it returns store, password is stored in a .git-credentials file in the user folder.

sudo cat ~/.git-credentials

If you have saved credentials locally, will yield
https://<USERNAME>:<PASSWORD_OR_TOKEN_IN_USE>@github.com

With the default configuration of git on windows, this is stored in Windows under: control panel => User => Credential manager.

See a more details answer here