To update your One X firmware you will need to perform the following:
Temporarily download/install the Insta360 app onto your mobile device.
Open the Insta360 App (this should automatically connect your camera - however if it doesn't go to WiFi and connect to the device just like the OpenSpace App).
Navigate to "Settings"
Scroll down to “Firmware Version”
Tap on “Firmware Version” to start the update process
Once the firmware is successfully updated please remove the Insta360 app from your mobile device (this can interfere with the functionality of the OpenSpace app).