How to send a password protected document?

Genius Fax doesn't support password-protected documents at the moment. We recommend that you remove the password beforehand.

You can do so with Preview on the Mac:

1. Open the document with Preview.
2. Enter password.
3. Select File > Print… 
4. Select Save as PDF in the bottom left corner of the screen.
5. Save to the desired location (eg. iCloud Drive)
6. You can now fax the document.