To control how your website is displayed when shared on Facebook & Twitter, the merchant is encouraged to set up the SEO field under “G. My Store -> 3. Store Setting -> Social Media”.

For Facebook

og:url – your website url
og: title – title of your page
og:desc – brief description of your site
og: site_name – your website name
og:img – a link to a picture that will be displayed in the post

Facebook App ID: Is a unique number for Facebook to know who you are.
Refer here to know How to get Facebook App ID

*All the fields above are compulsory to fill up.

This is how those tags look on Facebook:

For Twitter

This is how the tags look on Twitter: