You can configure controls on the Settings / Controls screen. Choose from Tilt steering, Touch steering and other options. For Tilt steering, you can toggle Camera Tilt on/off and configure Steering Sensitivity.
If your Tilt steering is not working at all, your device may have lost calibration. Often this can be fixed by shutting down and restarting your device, or by using a 3rd party app to re-calibrate your accelerometer.