The Started Order event must be pushed to the digitalData.events array when the page of the first step of the checkout funnel is loaded. Usually the order is started from the page where the user is given the choice of ordering as a guest or as an authorized user.

From the site code / when using AJAX

digitalData.events.push({
  category: 'Ecommerce',
  name: 'Started Order',
  cart: digitalData.cart
});

From the SegmentStream interface

Trigger: event Viewed Page

Event handler:

if (
  _digitalData('page.type') === 'checkout' &&
  _digitalData('page.category') === 'Authorization'
  ) {
  return {
    category: 'Ecommerce',
    name: 'Viewed Cart',
    cart: _digitalData('cart')
  };
}

Required by the following integrations:

Other body