Press and release the Reset Button. Once you do that the LED on your Cloud Beacon should turn on with light blue light. When it's on, you need to press and release the Action Button.
Please be aware that if you press the action button before the LED turns on, or after it turns off, you won't be able to enter the Configuration mode, and you will need to try again by pressing the Reset button.
When you successfully press the combination of the Reset and Action buttons, the LED on your Cloud Beacon will be constantly blinking in the light blue colour.
Please note that it's possible you will see a Cloud Beacon's LED blinking in dark blue. It means that you didn't press the action button at the right time. You might see this only on new Cloud Beacons that haven't been configured yet. If this happens, please try entering the Configuration mode once again, paying close attention when exactly you press the Action button.