Hi @Chakiry,
Thank you for sharing this information with the Klaviyo Community.
In addition to taking into consideration the points made by @mkprkr, you will have to add a discrete item to your cart after you have self-identified your browser to log an Added to Cart event. And, as @mkprkr pointed out, self-identifying the browser can be achieved by following the instructions here. Only after this step is done, will an Added to Cart metric appear under Analytics > Metrics in Klaviyo after you add an item to your cart.
Also, you must already have Viewed Product tracking installed in order for the Added to Cart event to appear and function . The Viewed Product snippet must be installed above the Added to Cart snippet in the code for your website. We have more details in our article on this topic here.
Thanks, and have a great day.