Capabilities/mod/appointment:managecustomfields
From MoodleDocs

- This allows a user to manage site-wide custom fields for appointment sessions.
- This capability is not allowed by default for any roles.
Note: You are currently viewing documentation for Moodle 4.0. Up-to-date documentation for the latest stable version of Moodle may be available here: Capabilities/mod/appointment:managecustomfields.