When you aren't on a platform with a native keychain manager (e.g. macOS, Linux+GNOME/KDE), ZED_KEYRING_PASSWORD is what's used to encrypt files on disk that store credentials in $HOME/.zed or $XDG_CONFIG_HOME/zed. The first time you create a context, it'll prompt you to create a password to encrypt that configuration. Going forward, whenever zed needs to access those credentials, it'll prompt you for that password, just like the keychain on your system
you can delete
.zed
folder to recreate the keyring password