the_content() function modification

Hi Experts!

In my site, i’ve updated the single.php file with a THML Table and all data are coming from Custom Field. For photos, i Upload the photo in Media and use the URL in Custom Field to load the photo in Table. Basically I don’t keep any information in post box which is actually returned by the_content() function. But I add photo as featured photo.
But as a result many times when I share my post links, the site or service don’t show the actual photo of the post. I was wondering If I replace the full table from single.php file into the_content() function, is it possible those sites will show the photos when I share my links?

Waiting for help 🙁