Field sku doesn't exist on type FulfillmentOrderLineItem

[arturo82]

Hello, I try display all information of products by orders. I put this code

orders( first: 10 reverse:true, query:"fulfillment_location_id:8541236588 AND financial_status:paid AND fulfillment_status:unfulfilled") {

......

fulfillmentOrders(first: 4,query:"assigned_location_id:8541236588 ") {
edges {
node {
id
status
assignedLocation{location{id}}
lineItems(first:6){
edges{
node{
id

sku
}
}

.....

the error is 'Field 'sku' doesn't exist on type 'FulfillmentOrderLineItem