Go to the "Customers" page within the "Customers" menu, locate the customer you are searhing for, and consider his / her customer profile. In that profile, scroll down to the "Carts" portion, where you can see all the carts established by this customer. You can find other modules that display https://www.presta-addons-modules.com/es/free-modules/prestashop-popup-on-exit-page-on-browser-tab-close-event.html