If your interview has expired there is a button on the interview box where you can select “Request more time”. This request is sent to the employer and if they decide to grant you an extension, you will be notified.
Please note that candidates are generally given 4 days to complete an interview. A reminder email is also sent out 48 hours prior to the interview expiring. In some cases the deadline may have been set to less than 4 days by the employer.