What is the ESSAPPS_ discount code in the cart, and can I rename it? (Essential Free Gift BOGO BXGY app)

Each offer applies its gift through a Shopify discount. Its name is set in the Discount section at the bottom of the Offer tab, under Discount code.

A new offer gets a generated name, such as ESSAPPS_77YFI3. As the editor notes, this name is visible to customers in the cart and at checkout.

You can change it to something clearer, such as FREEGIFT or SUMMER-GIFT. It can be up to 40 characters. Save the offer after changing it.