put https://{merchant}.fulfil.io/services/3pl/v1/inbound-transfers/acknowledge.json
You should acknowledge a 'pending' internal shipment when it has been successfully imported into the 3PL's WMS. Acknowledging the shipment helps the customer service team at the merchant gain visibility into the transfer process.
{
"shipments": [
{
"id": 461
},
{
"id": 560
}
]
}