Sometimes candidates can lose internet connection or for any other reason you might want to give them another chance to take the test. Reopen the test session for the candidate by going to their test report and clicking on "Reopen" in the top right corner of the test report.
After you click on the link you will have the option of opening any of the tasks or all of them as well as changing the time limit for the test. Click on "Reopen the test session" to confirm changes. Your Candidate can use the same test session invitation link as during their latest attempt.