How can I configure taxes included in price

To configure taxes included in price, you must first create a tax in the dashboard and make sure the Included in price option is checked:

Then, when you define your product, you need to add the data-item-has-taxes-included attribute, and set the value to true:

<button class="snipcart-add-item"
  data-item-price="20"
  data-item-name="Product"
  data-item-id="1"
  data-item-url="/"
  data-item-has-taxes-included="true">Add to cart</button>

Then, taxes will be calculated by assuming that the price of an item contains taxes. You’ll find more information about how this works right here.