When the candidate has finished the test, make sure they have clicked the "Finish" button otherwise the results won’t be recorded. 

When the test has been completed you should print out their certificate.  The option is do this is presented immediately after the "Finish" button is clicked.

If you accidentally click past this option it is still possible for the administrator to retrieve the certificate.  To do so, simply click on "Results & Certificates" on the Test Administration Panel.  You can then search by Test type and date, before selecting "Download certificate (pdf)" next to the required Test.