Add a product to the Cart using the WebService

[hrnsykk]

I want to add a product to the Cart using the Web Service from another site.

When I add a product to the Cart with the code below and redirect the user to the Cart page, the Cart appears empty.

But this Card has been added in BackOffice.

Where do I make a mistake?

 

<prestashop xmlns:xlink="http://www.w3.org/1999/xlink">
  <cart>
    <id_currency>1</id_currency>
    <id_lang>1</id_lang>
    <id_guest>0</id_guest>
    <associations>
      <cart_rows>
        <cart_row>
          <id_product>4700</id_product>
          <id_product_attribute>0</id_product_attribute>
          <quantity>1</quantity>
        </cart_row>
      </cart_rows>
    </associations>
  </cart>
</prestashop>