Sometimes when you try to share a link to your facebook page, facebook doesn’t show the link preview, it just displays the website url, here’s how you can fix it.
Fix Facebook not showing link preview
1. Visit Facebook share debugger page,
2. Paste the link for which the Preview was not displayed and click ‘Debug’.
3. Ignore the warnings and click ‘Scrape again’, now the debug tool will show the link preview at the bottom of the page correctly.
4. Go to your Facebook page and share the link, the preview will now work and you can publish the post without any problems.