The WCC user who wants to add a new tab in WCC needs to be added in an EEM policy for WCC named ConfigurationControllExternalAppsAdminDefault.
Here are the steps:
1. Login to EEM WCC0004 Application.
2. In the Manage Access Polices tab, select ConfigurationControl and open the ConfigurationControlExternalAppsAdminDefault policy.
3. In the Identities section, use Search Identities to find the user or group that needs to add a new tab.
Click the right allow button to add the user or group to Selected Identities.
4. Make other change as appropriate.
5. Save the change.