OpenVPN client is available in App Store.
You need OpenVPN Connect version 1.0.7 or newer (AES-GCM cipher support)
Log in to WMI panel and download file vpn-users.ovpn from VPN section:
and open the file in OpenVPN Connect:
In app profile will appear as available for import. Choose an ADD option:
After successful profile import enter your login in a Username field and add configuration by clicking an ADD button. Confirm saving it in device's memory: