Customize the WooCommerce Checkout & Thank You Page with Cartflows

Ya i tried to follow this as well but when i hit global settings after picking the template and deleting the landing page. So i hit global settings and it just takes me to the show ready template for!!! nothing else it wont let me pick the checkout page

Hi, thank you for your sharing! But my Thank you page can't work, did you know what's wrong with it?