No, only one account is allowed. Even if you have the games downloaded separately, the account must be the same across all of them.
Always remember your registration method (Email Login // Google or Apple Login), as well as your username and password.
Having more than one account will result in being banned from the platform.
On the login screen, you have the option to reset your password by clicking the "I forgot my password" button. You can also send an email to support@backspingames.com if you can't find this option.