I wroted down a Google Tag Manager ID in the settings of a website. The GTM has one tag for pageviews and another tag for E-commerce transactions.
On the catalog list, I can add products to the cart by the "Add to cart" button, but a 404 error is displayed for the checkout page or when clicking on a product from the catalog list. Besides, Google Analytics tracks the data of the visits, but not the data of the E-commerce.
May I configure antything else or is it an error?