In case that your request contains objects (e.g. car -> color, size, etc.), you will have to create virtual models to process these objects later in your business processes. Do so by selecting "Model" in the parameter type selector, and introducing the child elements that you would need. You can nest the objects as many times as you need (i.e. object within object) and create virtual model arrays. In case that you have used the autofill, this process was completed automatically.