The resetByExistingPassword method wraps the Reset By Existing Password API endpoint. If this method succeeds, the Member will be logged in, granted an active session, and the session cookies will be minted and stored in the browser.
If there is a current Member Session, the SDK will call the endpoint with the session token. This will add the new factor to the existing Member Session.
If this method succeeds and the Member is not required to complete MFA, the Member will be logged in, granted an active session, and the session data will be persisted on device.
If this method succeeds and MFA is required, the intermediate session token will be persisted on device.
You can listen for successful login events anywhere in the codebase with the stytch.session.onChange() method or useStytchMemberSession hook.