When I put https://ankiweb.net/shared/info/368380974 into a post on this forum, it shows in the preview:
https://ankiweb.net/shared/info/368380974
Sorry, we were unable to generate a preview for this web page, because the following oEmbed / OpenGraph tags could not be found: description, image
When I put https://docs.ankiweb.net/deck-options.html, it shows:
Deck Options - Anki Manual
Sorry, we were unable to generate a preview for this web page, because the following oEmbed / OpenGraph tags could not be found: description, image