Normally usernames and passwords are issued by e-mail either by you or Wizerize depending on the actual case.
A) If you distributed the passwords yourself:
Find the e-mail and resend the users log in information.
If you cannot find it ask email@example.com to issue a new user/password.
Be aware that your e-mails might end up in spamfilter - so make sure that the user has received your e-mail.
B) If Wizerize distributed the password:
All If a user for some reason has not received the e-mail it might be caught in the spam filter or the user might have deleted it – ask firstname.lastname@example.org to resend the information.