If you have downloaded IL Print and it is not being read by the printer setup in Firefox, you will need to add the certificate to your browser first. Here's how!
1. Type https://localhost:9191 into your Firefox browser. Hit Enter.
2. You will see a page warning you of a potential security risk. Click "Advanced".
3. Click "Accept the Risk and Continue".
4. When you see an HTTP ERROR: 404 page, it means the certificate has been added correctly.