It usually takes 48 hours to authenticate, on average. But, if it has been longer than that, consider sending a message to Shopify support, and they can look into the account. Contact page link: https://help.shopify.com/en/questions#/contact/
Nick | Ecommerce & Marketing Technology Consultant | Toronto, CANADA. - For consulting work availability, please send me a Private Message or submit a ✍️Contact Form. - For FREE Shopify Tutorials, ✅Subscribe to my YouTube channel (▶️ Ecommerce TV).