Discourse-github not posting any linkback

Having a look deeper into the plugin’s code to hopefully see if there was parameters that need to be met and found the following.

!!(SiteSetting.github_linkback_enabled? &&
      SiteSetting.enable_discourse_github_plugin? &&
      @post.present? &&
      @post.post_type == Post.types[:regular] &&
      @post.raw =~ /github\.com/ &&
      Guardian.new.can_see?(@post) &&
      @post.topic.visible?)

Now I don’t know all the variables but the post.topic.visible would that mean it needs to be in a public category for it to be linked back? My first couple of attempts where in categories that were only visible to the moderators that didn’t seem to work, is that a possible reason it didn’t work or through an error?

Any insight on the other parameters/requirements would be much appreciated.