By default you will most likely be unable to post to your WordPress blog due to security restrictions on your server.
Your options are:
SCM uses either the WP-JSON or the XMLRPC to upload posts to your blogs.
The XMLRPC is older and by default disabled on most servers.
The WP-JSON is newer but requires you login to your blog and create an Application Password.
We can find solutions to most errors by using WP-JSON first by generating and application password.
If that fails, we can try to install the basic auth plugin.
If that fails, as a last resort we can rename the xmlrpc.php file and use the newly renamed file to post articles.
How to test a blog connection
When you add a new blog, there is a test button.
Click Edit blogs
Next to each blog is a test button
Click test
If it works you get a message
If it fails you get a popup
The popup gives you some ideas on how to fix the problem