Start Smart Checkout by URL

If the Smart Transaction is prepared for checkout, you can access the checkout URL in the field /checkout_links/url_checkout:

Smart Transaction

{
    "object": "smart.transactions",
    "id": "STX_2AUSR7M6B2NHPG3C4JTKBEY07YXSAZ",
    ...
    "checkout_links": {
        "url_checkout": "https://checkout.secupay.com?wizardFlow=checkout&stx=STX_2AUSR7M6B2NHPG3C4JTKBEY07YXSAZ&viewMode=fullscreen"
    },
    ...
}

It is up to the merchant to offer this URL to the prospective customer.

A few suggestions:

It can be opened full screen in a browser using an <a> tag.
It can be sent via e-mail or in a chat window to a known customer.

When you integrate it into a web application you should define return URLs. There is a section below, that describes how to define them. But as you see it is not bound to a website or web application.

When you open the Smart Checkout in a layer, you need to consider that it might switch to full screen mode. This is needed for instance for the 3-D Secure checks.

The return URLs will always open in full screen and replace the former window.