curl --request POST \
  --url https://api.{your-broker}.slate-labs.com/orders/preflight \
  --header 'Content-Type: application/json' \
  --data '
{
  "symbol": "<string>",
  "action": "<string>",
  "requested_at": "2023-11-07T05:31:56Z"
}
'

{
  "block": "<string>",
  "ends_at": "2023-11-07T05:31:56Z",
  "message": "<string>"
}