Because of what the link to my site is not attached to the post in classmates?

Question

Django

Because of what the link to my site is not attached to the post in classmates?
At the same time, links to other sites are attached automatically. I don’t even understand where to look for a jamb, since there is no information on this matter.
My site is built with Django if that matters.

Answer 1

The html must have description or meta description tags.

Answer 2

The title of the page must be specified.
If you want the default image to be displayed when publishing a link, you must specify the tag

<meta property="og:image" content="http://[абсолютный url картинки]"/>