It is very easy to activate the WPS on your router.
1
WPS button
To do so, press the WPSbutton for 4 seconds on the Mesh unit that is connected to your router/modem by RJ45.
2
Wi-Fi devices list
Now go the the Network selection of your device (phone, computer, printer, etc.) and the new device added to the network should appear and you can now connect to its network.