Download Stable version of Tunnelblick on your computer from official website. Be sure that you download version of program which works with your macOS version.
Run installator. Then double-click on the icon Tunnelblick.app.
Allow to open the program.
Enter Username and Password from your account on macOS.
Tunnelblick installed. Click I have configuration files.
In the "My Account" download Tunnelblick files and unzip the archive to any folder.
In the top menu bar macOS find Tunnelblick icon and then click VPN Details.
You must drag and drop the files from the Finder to the Configuration section of the program Tunnelblick to upload configuration files.
Click Apply to all so that all files are successfully loaded. And choose to install files only to your account or to All Users macOS.
Enter your login and password on the account macOS.
To connect to OpenVPN, click on the Tunnelblick icon in the top menu bar and select the desired connection.
In the next window select:
Connection successfully established.