curl -X POST 'https://developers.flouci.com/partners/transactions/init_pos_transaction' \
  -H 'Authorization: Bearer <APP_PUBLIC>:<APP_SECRET>' \
  -H 'Content-Type: application/json' \
  -d '{
    "id_terminal": "terminal",
    "serial_number": "SN123456",
    "amount_in_millimes": 1000,
    "payment_method": "WALLET",
    "developer_tracking_id": "dev_track_123"
  }'

{
  "success": true,
  "terminal_id": "terminal",
  "developer_tracking_id": "dev_track_123",
  "message": "Transaction initiated successfully",
  "status_code": 201
}