This feature is available on Ruuvi Station mobile app only. Firmware update requires physical access to your Ruuvi sensor and can only be updated using Bluetooth connection on your mobile device.
Here, you are able to see the current firmware version installed on your Ruuvi sensor device and update your firmware to the latest version.
Always keep your sensor firmware up-to-date. Updating requires you to have physical access to the Ruuvi sensor in order to push the button or buttons on the device depending on the model inside the sensor. To press the buttons, you must remove the sensor cover.
Follow the instructions given on the screen to update your sensor firmware.