Buyers still land on Shopify checkout

• Not live yet, or paused: buyers only reach Payd after Go live. Before that, only your own browser in preview does.
• The line isn’t loading: click Check installation in setup. It must be in the theme that’s live, in the footer.
• Buy it now or Shop Pay buttons: they skip the cart and go straight to Shopify (turn them off).
• A cart app with its own button: add data-payd-checkout to it (install).
• A cart Payd hands to Shopify on purpose: gift cards, subscriptions, automatic discounts, other currencies (the list).

Your store’s Settings has a health check that re-checks Shopify, Whop and the install line in one go.