Send Certificates at a Later Time
Certify'em is designed to send certificates immediately upon submission of your exam. Even if you configure your Google Form settings to release scores "Later, after manual review", this will not change how Certify'em behaves (due to a technical limitation).
If you wish to delay the sending of certificates in your exam, you can still achieve it through these steps:
Configure Certify'em settings by choosing passing score, certificate template, advanced options, etc.
Turn certification ON. Once ON, immediately turn certification back OFF. This step ensures that all settings are configured properly (for later sending of certificates). By keeping certification OFF, you ensure that certificates will not be sent out automatically.
In your Google Forms settings ("Responses" tab), set the Form to accept responses (turning certification OFF automatically stops accepting responses).
Let people take your exam.
[Optional] Score any responses that could not be auto-scored (i.e. free response text questions).
At a later date (but within 30 days!), choose "Resend Certificates" from the Certify'em Add-on menu. Here you will see displayed the last 30 days of responses to your Google Form/Quiz.
Click "Reprocess" next to any entries you wish to send certificates for.
Once a response has been processed (i.e. certificate sent for response with a passing score), the "Already Processed?" entry for that response will change to "Yes".
Note that daily limits and quotas still apply when using this method.