Pre-fill WooCommerce Checkout Fields
Gets any URL variables you send to a WooCommerce checkout page where the visitor is not otherwise registered and logged-in. This function fills in the three fields with the data passed in the URL string.
Use with a LeadMagnet product or when sending a new lead or prospect from another website or social media.
If prospect has already provided their first and last name and email, this eliminates the need for them to add this information again in the WooCommerce checkout.
*Note: after they complete the first transaction on your site (free or paid), their user information is always pre-filled by WooCommerce.
Therefore use this for situations where the visitor is new, rather than returning customer.