Can't configure easy-rsa as vars file didn't exist

I'm trying to set up open vpn latest version on CentOS 7 following this tutorial https://www.hugeserver.com/kb/how-to-config-openvpn-linux-server/

The problem was there was no "vars" file to edit.

I checked every folder in easy-rsa including 3, 3.0, 3.0.3 and didn't find any "vars" file inside them.