SwitchiFy can be configured in two ways. The first one is 4-way switching mode. And the Wiring goes like this:
Connect the phase and Neutral to the screw terminals next to the Hi-Link Module.
In the above picture, Switch 1 and Switch 2 are the generally available 3-way switch. In general, you house wiring guy would have wired like this: The top and bottom terminals of each switch are connected to each other. And the middle one of the Switch 1 will be connected to phase, middle one of the Switch 2 will be connected to one terminal of the appliance (light in this example). The other terminal of the appliance will be connected to neutral.
To configure the SwitchiFy in 4-way mode, we have to connect the board between Switch 1 and Switch 2. Don't disturb the middle terminal of the Switch 1 and Switch 2. Take the top and bottom terminal of the Switch 1 and connect it to the screw terminal marked "Incoming Line" (Orange and Blue wire in the above picture). Take the top and bottom terminal of the Switch 2 and connect it to the screw terminal marked "Outgoing Line".
You are good to go. Open the app and test it like shown in this video: