Start by checking if networkmanager for OpenVPN is installed. Do that by opening a terminal and running:
pacman -Q networkmanager-openvpn
If networkmanager for OpenVPN is installed, you should see:
If networkmanager isn't installed, run:
pacman -S networkmanager-openvpn
systemctl restart networkmanager
Right-click on the icon in the status bar that's related to network. Choose Configure Network Connections. Right-click on the network connection you're using. Click on Edit in the new menu.
On tab, General configuration, choose Automatically connect to VPN when using this connection to enable automatic connection to OVPN for the chosen network. If you can't select it yet, you can go back later in the guide and re-do this step.
On tab, IPv4, click on Method. Choose Automatic (Only addresses).
For field, DNS Servers, enter:
On tab, IPv6, click on Method. Choose Automatic (Only DHCP).
Click on OK.
Double-click the file to extract the content.
In windows, Connection editor, click on File and then Import VPN. Go to the directory where the configuration file was downloaded and choose the file that ends with .ovpn.
If you get the following question: Do you want to copy your certificates to /home/USER/.local/share/networkmanagement/certificates/? Choose Yes.
Right-click on the created VPN profile. Choos Edit.
On tab, General configuration, make sure that All users may connect to this network isn't selected.
On tab, VPN (openvpn), enter your username and password for your OVPN account. Choose Store in order to save your credentials.
In window, Connection editor, right-click on the VPN profile and choose Connect.