you can enable Two-Factor Authentication from within the webmail interface of an email account in cPanel. For this option to be available, two-factor authentication must be enabled through WHM and included in the account's feature list. 

To enable Two Factor Authentication in Webmail:

1. Log into webmail either through the cPanel or the Webmail login portal
2. From the Webmail management screen (before you access RoundCube), under the header Edit Your Settings, select Two Factor Authentication
3. Click on "Setup Two Factor Authentication."
4. Follow the provided instructions to set up Two Factor Authentication with your preferred application.