returnUrl/cancelUrl + customer creditcard and billing/shipping details. Some keys (e.g. "amount") are overwritten with data from the associated . If this array is constructed from user data (e.g. a form submission), please take care to whitelist accepted fields, in order to ensure sensitive gateway parameters like "freeShipping" can't be set. If using , only fields which exist in the form are returned, effectively whitelisting against arbitrary user input.