The example I gave was not as clear as it could have been. I’ll edit it this week. The localhost:3000 domain is the domain of my local development site. You should replace that domain with the actual domain of your forum. For example, https://forum.example.com/session/sso
If this is the case, then you do not need to configure any of the Commenting or Publishing settings.
When SSO is enabled, all users on your WordPress site will be able to login to your Discourse forum. If you have users on WordPress who should not be allowed to create accounts on Discourse, you will need to add some code to a plugin or your site’s theme. The topic gives details about how to accomplish that: How to prevent some WP users from being able to login to Discourse.