Age verification on the checkout

I have a client in New Zealand who requires an Age Verification on the checkout of the webpage. The client sells alcohol online and the licensing office will not renew her license unless there is an Age Verification tick box on the actually checkout page. 
Is there coding or a 3rd party widget to help with this. I've tried Elfsight, among others, but no luck. 

Thanks, I'll see if this will keep the license board happy. 

we have the same problem in denmark from oct 1. 2024. Age verification needs to be with passwort/drivers license or MITID

Will need a solution soon or will have to change to shopify

/Rasmus

www.cava.dk