Yes, SAP Fiori can be accessed using internet via webdispacther. The SAP webdispatcher has to be installed and configured to access the fiori in the internet. The SAP Web Dispatcher is needed for routing and distributing the network calls to the correct systems. Between the Internet and your SAP system lies the SAP Web dispatcher. Consisting of one or more SAP NetWeaver application servers, it is the entry point for HTTP(s) requests into your device. The SAP Web dispatcher can reject or accept connections as a "software web switch". It balances the load when it accepts a connection to ensure an even distribution across the servers.