Wix themes crop titles, excerpts, and cover images according to the blog layout. A heading that fits the editor can wrap badly in the post list. Send a draft, open the Wix blog editor, and look at the list view and the post view. Set the excerpt and the cover there if the theme expects them and the draft arrived without them. Then choose Published from WritingTools only if you do not need those extra fields, or publish from Wix after you have set them.
The API key’s permission is the whole security boundary. A key that can manage blog posts can create posts. Store it in the connection, not in a shared document. If you create a new key in Wix, edit this connection and replace the old one. Disconnect when the site should stop receiving drafts. The name you gave the connection is what the editor shows, so a name like the site’s domain is more useful than “Wix 2.”
Richer Wix content, such as a store product or a static page section, is outside this card. For a custom system that should receive the same article as JSON, use a webhook instead of stretching the blog API. If the test draft is removed and you never see it, that is the success case: the check creates it and deletes it. A draft you send later from the editor is a different post, and that one stays until you publish or delete it in Wix. Keep the site ID next to the site name in your own notes, because the ID is not shown on the public blog. A second Wix site needs a second connection with its own site ID. Reusing the ID from a different site creates the test draft in the wrong blog, which is easy to miss if you only look at the success message.