You can use the app called Bouncer to deter under-age visitors by having them verify their age via birthday, Facebook or self-certification.
While we cannot give explicit legal advice, we do recommend seeking legal counsel to ensure you’re 100% certain you’re all set to sell your age restricted products.
I only want to check age when a visitor checks out with certain items in their cart. Most of my products are not age restricted, so I don’t want to ask irrelevant questions to my potential customers.
I possibly need to look at age when a guest checks with specific things in their truck. The greater part of my items are not age limited, so I would rather not pose unimportant inquiries to my possible clients.