Yes, you can. You can go to the 'Invites' tab - Select the candidate and in the action strip on the right side, click on the 'Send Candidate Reminder' widget to send a reminder email to the candidate
'Invites Tab' -> Click on the Candidate row -> click on the 'Send Candidate Reminder' widget -> Email reminder goes to the candidate
You can also go to the 'Assessments' tab and do the same:
'Assessments Tab' -> Click on the appropriate Assessment -> Click on 'Invites Tab' on left panel of the Assessment-> Choose the candidate and use the Action Strip, clicking on the 'Send Candidate Reminder'