[Twenty Fourteen] facebook thumbnails not showing

Whenever I share my link and it doesn’t have a featured image attached, no image will show up and rather I get a blank space.

I tried this site’s info –
https://www.wpbeginner.com/wp-themes/how-to-avoid-no-thumbnail-issue-while-sharing-post-on-facebook/

Sites url – https://goodmusicinc.net/