How to send Faxes via Email? The Faxes Sent via Email section is missing from Fax settings.

I'm following these instructions: https://support.ringcentral.com/article-v2/Setting-up-a-fax-cover-page.html?brand=RingCentral&product=MVP&language=en_US

The "Faxes Sent via Email" section shown in the documentation simply doesn't exist in the "Fax Settings" section, so I can't add an email that has permission to fax. This section is missing when I look at it from the admin side and from the individual user side.

Notice also that I am not able to check the checkbox "Allow this user to send faxes using Email-to-fax"