Add to cart results in immediate display of checkout page

Hi,
When I copy the link (which can be viewed in the product page when clicking the button HTML link 'Add to shopping cart'), paste it in a webpage and the user clicks that link immediately the checkout page is shown.
What I expect that the item is only added to the shopping cart and the user will stay at the same page. That at least is the functionality when in the web shop itself when he user clicks 'Add to the cart' for that particular product.

You may see the undesired functionality when going to yourinnervoice.nl, select US English at the top, click on the offcanvas menu, click Sessions and click on of the options in the circles near the end of the page.

Can this undesired be avoided in some way?

Thanks as usual for your excellent support.

Ynze van der Ree