openvpn is not defined

[MurhafSousli]

I am trying to use this library, I have the following

  openvpnBin
    .initialize(path.normalize('c:/Program Files/OpenVPN/bin/openvpn.exe'), {
      host: '176.126.237.217',
      port: 443,
      config: path.normalize('./ovpn/vpnbook-euro1-tcp443.ovpn')
    })
    .then(function() {
      console.log('openvpn running');

      const managerInstance = openvpnmanager.connect({
        host: '176.126.237.217',
        port: 443
      });

      managerInstance.on('connected', function() {
        managerInstance.authorize({
          user: 'vpnbook',
          pass: 'xf5s3d9'
        });
      });

      managerInstance.on('console-output', function(output) {
        console.log(output);
      });
    });

console log

openvpn running
Unhandled rejection ReferenceError: openvpn is not defined

Any ideas?