When your label has been created, you will get the event payload as below.
{
"event_type": "shipment.label.created",
"resource_type": "shipment",
"resource_id": "ESTEST00000",
"data": {
"easyship_shipment_id": "ESTEST00000",
"platform_order_number": "#100001",
"status": "success",
"label_url": "https://goeasyship.s3.amazonaws.com/ESTEST00000_label.pdf",
"tracking_number": "12345",
"tracking_page_url": "https://www.trackmyshipment.co/shipment-tracking/ESTEST00000"
}
}