PDII Web TestEngine demo

Consider the following code snippet:

HTML

<c-selected-order>

<template for:each={orders.data} for:item="order">

<c-order orderId={order.Id}></c-order>

</template>

</c-selected-order>

How should <c-order> component communicate to the <c-order-order> component that an order has been selected by the user?