Help & troubleshooting for network issues, including connecting your device to your home Wi-Fi network, connecting to public networks, troubleshooting wireless issues & ethernet connections, and optimizing streaming performance.
You need an internet connection to stream the Roku device.
The normal manner to access the internet is through a modem/router or using a mobile hotspot. Mobile hotspots are usually very limited in high speed data allowance so not ideal, nor recommended for streaming.
Basically, you need some sort of home internet service and use a modem/router ideally for streaming.