Blog posts, also known as articles, are composed in the Shopify admin and their appearance is controlled by the theme. 
Access the theme's blog post settings
Navigate to any article in the theme editor preview or select Blog posts from the template selector dropdown.
In the left sidebar settings, open the Article settings.
Activate social share buttons
Share buttons allow customers to post the article to their preferred social media platform with ease.
To enable share buttons, select Show share buttons.
