First, locate the class: click Classes from the left main navigation. Search for the class you would like to generate credentials for and click the Class Title.
Now that you are viewing the class, locate the participant's section and select the applicable participants. If none are selected, you will only have the option to download all class credentials.
Navigate to the bottom left and click Actions.
Hover over Download PDF, then click Credentials if you selected specific participants or click All Participants for full class export.