You should always check the sensor availability before attempting to use it.
Returns whether the gyroscope is enabled on the device.
On mobile web, you must first invoke Permissions.askAsync(Permissions.MOTION) in a user interaction (i.e. touch event) before you can use this module. If the status is not equal to granted then you should inform the end user that they may have to open settings.
On web this starts a timer and waits to see if an event is fired. This should predict if the iOS device has the device orientation API disabled in Settings > Safari > Motion & Orientation Access. Some devices will also not fire if the site isn't hosted with HTTPS as DeviceMotion is now considered a secure API. There is no formal API for detecting the status of DeviceMotion so this API can sometimes be unreliable on web.