Setup a IKEv2 based VPN server

Now my new server is a dedicated machine in Paris.
AP8,1 allows VPN using IKEv2, so I tried ti set it up on my new server following this tutorial:
https://www.zeitgeist.se/2013/11/22/strongswan-howto-create-your-own-vpn/

Doesn't work yet. Main drawback: WP8.1 VPN setup screen claims I don't have any certificates installed! (of course I imported both the CA Root and my client P12 cert).

What about username+password EAP based authentication? Will try when I'm out of office wifi.