Hit the button in the Ozom App to set the Ozom Box into search mode.
Find a plug near your OZOM Box to plug the Siren in.
Keep the LED-button on your device (see blue arrow) pressed until you hear a beep and it starts to flash in red. This indicates that the adding process has started.
It may take some time (up to a few minutes) before the OZOM App connects to the Siren and displays a progress bar.
If adding is not succesful, wait until the blue button turned blue again. Unplug the siren. Then start again from Step 1.