Failure in inventory interaction, fails the order

$ curl $OKAPI/orders/composite-orders -H "X-Okapi-Token: $TOKEN" -w'\n' -H "Content-type: application/json" -XPOST -d '
{
  "vendor": "09c6ed1b-3984-4d9a-8f9b-e1200b68b61c",
  "orderType": "One-Time",
  "compositePoLines": [
  {
    "titleOrPackage": "",
    "orderFormat": "Physical Resource",
    "cost": {
      "currency": "USD",
      "listUnitPrice": 10.0,
      "quantityPhysical": 2,
      "poLineEstimatedPrice": 20.0
    },
    "source": "User",
    "acquisitionMethod": "Purchase",
    "locations": [
    {
      "locationId": "758258bc-ecc1-41b8-abca-f7b610822ffd",
      "quantity": 2,
      "quantityPhysical": 2
    }]
  }]
}'
{
  "errors" : [ {
    "message" : "The Material Type is required but not available in PO line",
    "code" : "materialTypeRequired",
    "parameters" : [ ]
  } ],
  "total_records" : 1
}