curl -X POST '{backend_url}/admin/orders/{id}/fulfillments/{fulfillment_id}/shipments' \
-H 'Authorization: Bearer {access_token}' \
-H 'Content-Type: application/json' \
--data-raw '{
"items": [
{
"id": "id_3QQtl2VvE73c",
"quantity": 6772917941567488
}
],
"metadata": {}
}'