Setting up Pixel in Shopify
To measure and monitor your Shopify store in your Facebook/Meta Business Manager - Ads Account, connect them together using a "Pixel." This is a snippet of code that is placed in your store's programming code to watch the behaviour of visitors to help you improve your advertising.
Please use the most up-to-date help by going here:
https://help.shopify.com/en/manual/promoting-marketing/analyze-marketing/facebook-pixel