In order to connect to OVPN - you will first need to disable IPv6.
Navigate to App center → QVPN Service.
Add a new VPN client by starting the QVPN Service. Navigate to VPN Client → VPN Connection profiles.
Click on Add and choose OpenVPN. In the prompt that opens, choose the configuration file you downloaded in the previous step.
In the new prompt, fill out the following details:
Click on Apply.
Click on Connect for the created profile. After a while, it should clearly state that you are connected.