If your application is selected for audit, you would need to provide a copy of the certificate(s) of completion for your class(es). Each certificate should show the name of student, course name, passing grade, date of completion, and accredited institution name. Depending on the provider, you may need to complete additional coursework/quizzes to earn the recognition from the accredited institution.
If the online provider itself is accredited, a transcript or certificate from the provider is sufficient. If the course comes from an accredited institution but does not offer official documentation such as a certificate, you would need to demonstrate completion by obtaining another type of official documentation. A screenshot may be sufficient only if there is no other option and if it includes all required information: name of student, course name, passing grade, date of completion, and accredited institution name.