After using the Open graph section mentioned by Alan, we found that it still didn't work, the info we were inputting still didn't get rendered in the page at all. Turns out it's because of the Facebook SDK script included in the Default social media group's "Common Code Snippet" at the path : /sitecore/content/Tenant/Home/Settings/Social Media Groups/Default.
We finally solved the issue by making the default item and its children unpublishable, and I believe this can also be solved by removing the common code snippet if it's of no use to you.
Once we made it unpublishable, any info we inputted in the "Open graph" section of an item would appear just fine.