With OVPN you can tunnel your data over both IPv4 and IPv6. Do note that certain devices do not have support for IPv6 which means that your connection may fail with IPv6 activated on your account.
You can activate/deactivate tunneling over IPv6 for your account on the Settings tab in the client, or in the dashboard on our website, on OpenVPN → Settings.
After you have activated/inactivated IPv6 on your account you need to restart your connection by disconnecting and then reconnecting again.