On Dynamics 365 (online) web, "Work Time" is displayed with the following steps.
But when switching it to Unified Interface, "Work Time" is not displayed.
"Work Time" should be displayed both on Unified Interface and on Web.

-Steps-
1. Click "Field Service" - "Management" - "Resource".
2. Click a record from "Bookable Resources".
3. On Navigation bar, click the icon next to "Bookable Resources", click "Work Time".