Using XAMPP on Mac

I have installed <https://www.drupal.org/project/smtp>

After setting up **admin/config/system/smtp**

[![enter image description here](https://i.stack.imgur.com/ESuq4.png)](https://i.stack.imgur.com/ESuq4.png)

It gives above error. Unable to send test email.

Do we have to any setting on gmail or i'm missing anything?