FedEx - Label International Sender Pays Duties

{
  "carrier": "FedEx",
  "action": "SubmitShipment",
  "params": {
    "billing": [
      {
        "type": "duties",
        "payment_type": "SENDER"
      }
    ],
    "packages": [
      {
        "weight": 15
      }
    ],
    "customs": [
      {
        "customs_quantity_units": "EA",
        "customs_quantity": 1,
        "customs_line_amount": 50.00,
        "country_of_manufacture": "US",
        "customs_weight": 2.5,
        "customs_description": "My Description"
      }
    ],
    "currency": "USD",
    "shipper": "RocketShipIt",
    "ship_addr1": "123 Main St",
    "ship_city": "Whitehall",
    "ship_state": "MT",
    "ship_code": "59759",
    "ship_phone": "1231231234",
    "to_name": "John Doe",
    "to_addr1": "2000 Meadowvale Rd",
    "to_city": "Toronto",
    "to_state": "ON",
    "to_code": "M1B5K7",
    "to_country": "CA",
    "to_phone": "1231231234",
    "packaging_type": "YOUR_PACKAGING",
    "test": true
  }
}

<?php
$rs = new RocketShipIt;
$response = $rs->request(
array (
  'carrier' => 'FedEx',
  'action' => 'SubmitShipment',
  'params' => 
  array (
    'billing' => 
    array (
      0 => 
      array (
        'type' => 'duties',
        'payment_type' => 'SENDER',
      ),
    ),
    'packages' => 
    array (
      0 => 
      array (
        'weight' => 15,
      ),
    ),
    'customs' => 
    array (
      0 => 
      array (
        'customs_quantity_units' => 'EA',
        'customs_quantity' => 1,
        'customs_line_amount' => 50.0,
        'country_of_manufacture' => 'US',
        'customs_weight' => 2.5,
        'customs_description' => 'My Description',
      ),
    ),
    'currency' => 'USD',
    'shipper' => 'RocketShipIt',
    'ship_addr1' => '123 Main St',
    'ship_city' => 'Whitehall',
    'ship_state' => 'MT',
    'ship_code' => '59759',
    'ship_phone' => '1231231234',
    'to_name' => 'John Doe',
    'to_addr1' => '2000 Meadowvale Rd',
    'to_city' => 'Toronto',
    'to_state' => 'ON',
    'to_code' => 'M1B5K7',
    'to_country' => 'CA',
    'to_phone' => '1231231234',
    'packaging_type' => 'YOUR_PACKAGING',
    'test' => true,
  ),
)
);

rs.request(
  {'action': 'SubmitShipment',
 'carrier': 'FedEx',
 'params': {'billing': [{'payment_type': 'SENDER', 'type': 'duties'}],
            'currency': 'USD',
            'customs': [{'country_of_manufacture': 'US',
                         'customs_description': 'My Description',
                         'customs_line_amount': 50.0,
                         'customs_quantity': 1,
                         'customs_quantity_units': 'EA',
                         'customs_weight': 2.5}],
            'packages': [{'weight': 15}],
            'packaging_type': 'YOUR_PACKAGING',
            'ship_addr1': '123 Main St',
            'ship_city': 'Whitehall',
            'ship_code': '59759',
            'ship_phone': '1231231234',
            'ship_state': 'MT',
            'shipper': 'RocketShipIt',
            'test': True,
            'to_addr1': '2000 Meadowvale Rd',
            'to_city': 'Toronto',
            'to_code': 'M1B5K7',
            'to_country': 'CA',
            'to_name': 'John Doe',
            'to_phone': '1231231234',
            'to_state': 'ON'}}

)

rs.request(
  {"carrier"=>"FedEx",
 "action"=>"SubmitShipment",
 "params"=>
  {"billing"=>[{"type"=>"duties", "payment_type"=>"SENDER"}],
   "packages"=>[{"weight"=>15}],
   "customs"=>
    [{"customs_quantity_units"=>"EA",
      "customs_quantity"=>1,
      "customs_line_amount"=>50.0,
      "country_of_manufacture"=>"US",
      "customs_weight"=>2.5,
      "customs_description"=>"My Description"}],
   "currency"=>"USD",
   "shipper"=>"RocketShipIt",
   "ship_addr1"=>"123 Main St",
   "ship_city"=>"Whitehall",
   "ship_state"=>"MT",
   "ship_code"=>"59759",
   "ship_phone"=>"1231231234",
   "to_name"=>"John Doe",
   "to_addr1"=>"2000 Meadowvale Rd",
   "to_city"=>"Toronto",
   "to_state"=>"ON",
   "to_code"=>"M1B5K7",
   "to_country"=>"CA",
   "to_phone"=>"1231231234",
   "packaging_type"=>"YOUR_PACKAGING",
   "test"=>true}}

)

rocketshipit.request(
  {
  "carrier": "FedEx",
  "action": "SubmitShipment",
  "params": {
    "billing": [
      {
        "type": "duties",
        "payment_type": "SENDER"
      }
    ],
    "packages": [
      {
        "weight": 15
      }
    ],
    "customs": [
      {
        "customs_quantity_units": "EA",
        "customs_quantity": 1,
        "customs_line_amount": 50.00,
        "country_of_manufacture": "US",
        "customs_weight": 2.5,
        "customs_description": "My Description"
      }
    ],
    "currency": "USD",
    "shipper": "RocketShipIt",
    "ship_addr1": "123 Main St",
    "ship_city": "Whitehall",
    "ship_state": "MT",
    "ship_code": "59759",
    "ship_phone": "1231231234",
    "to_name": "John Doe",
    "to_addr1": "2000 Meadowvale Rd",
    "to_city": "Toronto",
    "to_state": "ON",
    "to_code": "M1B5K7",
    "to_country": "CA",
    "to_phone": "1231231234",
    "packaging_type": "YOUR_PACKAGING",
    "test": true
  }
}
)