Empty shopping cart before adding to cart

In Magento 2.2.5 I would like to delete / empty the shopping cart before the current product addtocart.

Review the following scenario:

  1. The new product has been added to the cart. The shopping cart user is not logged in. I have deactivated checking out guests so you need to log in.

  2. Suppose the customer has already added a product to the cart and the order has not been placed in the cart. This will be added to the current cart. But it should not