Creating an Email Opt-In for IG Checkout
Make it easy for Shop visitors become subscribers.

Invite your visitors to sign up for email on your Shop or at Checkout:
Email opt-ins allow customers to grant sellers permission to use their email address for marketing purposes
In Shops, you can also encourage more people to opt-in to emails by offering a percentage off their next purchase for your Shop.
Easily download the email opt-in list via Commerce Manager > Marketing List.
This feature is linked to your Privacy Policy
Your exported mail opt-in list will look like this:

For step-by-step instructions on how to create and set up email opt-ins, please review this Facebook help article.