I cannot configure Apple HomeKit

"If you have already configured HomeKit with another iOS device, please refer to the FAQ: ""How do I share the control of Apple HomeKit?"" to get an invitation.
Otherwise, follow the steps below:

First, reset the HomeKit pairing of your gateway:
 - Remove the gateway from the Home app in case you see it in your Home app.
 - Verify your smartphone is connected to the same Wi-Fi network as your gateway.
 - Verify that your gateway is powered and that no LED is blinking at the back of the gateway.
 - Press and hold the button marked with the gear icon.
 - When you see the LED blink red, release the button and press it once again quickly to confirm the reset.
 - The gateway will now reset and reboot automatically.
 - Wait until the LED at the back of the gateway glows white.
 
Second, reconfigure the Wi-Fi access of the gateway:
 - Open the VELUX app and select ""Settings""
 - Select "Home management"
 - Select "VELUX Gateway"
 - Select "Setup Wi-Fi" and follow the instructions.
 
Finally, pair your gateway with HomeKit:
 - Open the VELUX app and select "Settings"
 - Select "Home management"
 - Select "VELUX Gateway"
 - Select "Setup HomeKit" and follow the instructions.