For a candidate to be able to retake your test (i.e submit another attempt after the most recent one), you can either reinvite the Candidates to the same Test (When you do so, a Candidate's Test status initializes to “Invited”).
Note: When Candidates try to access a Test for a reattempt, sometimes, a browser level cache may disallow them from logging in to the Test. To overcome this issue, it is recommended that your Candidates access the Test link using a new browser window.
To re-invite candidates to a test, you can select one or more candidates from the candidates tab in your test, and click on 'Re-invite Candidate', as shown below. For more information on re-inviting candidates, please read the full article here.
Note:When you re-invite a candidate, the most recent attempt by the candidate is archived. A candidate can be re-invited as many times as needed.