For some reason, the default admin user account and password did not appear to exist in the instance of bitnami Joomla that I installed on my AWS through Lightsail.

To set your Joomla admin password:

  1. Log in using an SSH terminal. You can do this through your Web browser from your AWS control panel.
  2. Go to /apps/joomla.
  3. Type sudo ./bnconfig --userlogin admin --userpassword password
  4. You should now be able to log in using username: admin and password: password.