All sign-ins are done using email and password on the acandidate.com site.
When you’re invited to the system you’re asked to set your password, and if you forget it the best course of action is to ask for a password reset.
You can find more information on how to reset your password on this link https://help.acandidate.com/en/articles/9550509-i-forgot-my-password-now-what