I get the error authentication failed.

This error indicates that the username/email or password was not entered correctly.

1. Check your login data by logging in with the same data in the manufacturer portal of your PV system. 
2. Put the password back in the manufacturer portal and try to create your system with the new password.
3. If only one serial number or similar is necessary for the creation, check it again by job. Sometimes you can easily confuse an O and 0.