You may set a certificate at the course level, which would override the global default setup.
Create a course.
Click "Course Settings" tab.
Or navigate to the course.
Click the "EDIT" tab.
Click "Certificate" located on the vertical tab.
Map certificates, depending on the following:
Used for custom certificate mapping rules. Contact support for more information.
This section is used when a single certificate should be awarded to all learners completing the course.
Using this mapping will award a certificate based on the credit type the learner is awarded after completing a course.
No action: Will use the default mapping in the site for the credit type.
Prevent certificate: Will not award a certificate.