Prerequisite: The security key must have an NFC interface!
Open the login page on your mobile device. In the 2nd step (enter token), press the „Activate security key“ button:
At the same time, hold the security key close to the back of the smartphone (on an iOS device at the top end) and press the golden button:
You are now logged in.
Please note: Some mobile browsers do not support the U2F protocol. We have tested the login on Android with Google Chrome so far.