For help go to this link
https://vibethemes.com/envato/wplms/documentation/theme-guide.html#certificates
and
https://support.vibethemes.com/support/solutions/articles/1000165105-custom-certificates-with-printable-background-images-and-certificate-code-validation

[certificate_course]

[certificate_student_marks]

[certificate_student_date]

[certificate_student_email]

[certificate_code]