It is listed under Sales Reports > JTR Custom Tax, right after Taxes, and only when Business: Cart > Enable Custom Tax Calculation Systems is Yes; the menu link itself needs the Taxes sales-report permission. If you open the page directly and are sent back to the dashboard, the custom tax subsystem is either disabled or no tax provider is configured for the active kitchen. An empty table with "No custom-tax orders" simply means no paid orders in the range resolved to a jurisdiction.