https://www.facebook.com/987654321/posts/123456789

story_fbid is not directly used in the Graph API; instead, you’d use post_id in the format user_id_post_id .

https://m.facebook.com/story.php?story_fbid=XXXXX&id=YYYYY

It looks like you’re referencing a fragment of a Facebook URL:

If you have story_fbid and id :

The URL https://m.facebook.com/story.php?story_fbid= is a mobile-specific link designed to direct users to specific posts, identified by a unique numerical "story Facebook ID". These links may show as broken due to strict user privacy settings, deleted content, or the 24-hour expiration of Facebook Stories. To troubleshoot, users can replace the "m" with "www" for desktop viewing or use the Facebook Sharing Debugger to refresh the link's cache. For more details, visit Facebook Help Center . Fix Facebook broken link preview - ClickWP