Access the social media settings
Go to Customize > Theme settings > Social media to access these settings.
Set a default social sharing image
Click Select image to assign an image for links shared to social media platforms. Other images, such as product images or blog post featured images, will be used when links to these pages are shared—this setting is more of a backup, in case a link is shared and no image is provided.
Connect social media links
Expand beyond the Shopify platform by connecting your current social media URLs in the relevant fields. There are fields for Facebook, Twitter, Pinterest, Instagram, Tumblr, Vimeo, YouTube, and Linkedin. There is also a field for your store’s Email address.
These can appear as icons in the Footer.