Canonical tag issues

Hi there,

I’m struggling to find where and how to use this feature in the free version of the plugin. “Set canonical URLs to avoid duplicate content. Never have to worry about Google penalties again.” https://wordpress.org/plugins/wordpress-seo/

Can anyone help?

The page I need help with: [log in to see the link]