You will find the custom tabs’ settings in your WordPress admin area navigating to the LearnDash LMS menu ➡ Custom Tabs
1- Add a section title and other tabs.
2- Manage the tabs here with their icons and titles.
3- Enable the option to hide custom tabs for the logged out users, for the users who are not enrolled to the course(s) yet, and for the users who are unenrolled in the group(s).
4- Checkmark the boxes to display tabs on lessons/topics/quizzes and add tab’s content then update it.
5- You can view the custom tabs in the frontend user interface
Note: The same pattern of setting will be followed for lessons, topics as well as quizzes tabs.