Do I need a separate license for SAP Fiori?

No, you don't require any separate license for SAP Fiori components. The Fiori license cost is included in the SAP Gateway license, which is included in the SAP NetWeaver license. There is no extra cost required to access Fiori applications. SAP Fiori runs alongside the SAP Gateway system (Front End System). Based on the Fiori app requirement, the Fiori UI components are installed on the SAP Gateway system or in the backend system, in case of embedded Fiori deployment. As it comes along with the Gateway system, you don't need a separate license for SAP Fiori.