How can i get my VPN Ca certificate to setup build-in openvpn connection?

I have create my own vpn server but i can't setup the connection on kali linux build-in openvpn connection.
I have download my client.ovpn but can't open it as CA certificate to setup the connection.
I can only start the connection with openvpn --config client.ovpn --auth-user-pass
It will be easy for me to connect from the build-in wifi management connections.
How do i can get this CA certificate to make my connection work?

Best regards