USPS-REST - Get Purchase Token

{
  "carrier": "USPS-REST",
  "action": "PurchasePostage",
  "params": {
    "key": "your-key-from-authenticate-request",
    "account_number": "1000005549",
    "crid": "94879959",
    "mid": "901097701",
    "manifest_id": "901097701",
    "test": true
  }
}

<?php
$rs = new RocketShipIt;
$response = $rs->request(
array (
  'carrier' => 'USPS-REST',
  'action' => 'PurchasePostage',
  'params' => 
  array (
    'key' => 'your-key-from-authenticate-request',
    'account_number' => '1000005549',
    'crid' => '94879959',
    'mid' => '901097701',
    'manifest_id' => '901097701',
    'test' => true,
  ),
)
);

rs.request(
  {'action': 'PurchasePostage',
 'carrier': 'USPS-REST',
 'params': {'account_number': '1000005549',
            'crid': '94879959',
            'key': 'your-key-from-authenticate-request',
            'manifest_id': '901097701',
            'mid': '901097701',
            'test': True}}

)

rs.request(
  {"carrier"=>"USPS-REST",
 "action"=>"PurchasePostage",
 "params"=>
  {"key"=>"your-key-from-authenticate-request",
   "account_number"=>"1000005549",
   "crid"=>"94879959",
   "mid"=>"901097701",
   "manifest_id"=>"901097701",
   "test"=>true}}

)

rocketshipit.request(
  {
  "carrier": "USPS-REST",
  "action": "PurchasePostage",
  "params": {
    "key": "your-key-from-authenticate-request",
    "account_number": "1000005549",
    "crid": "94879959",
    "mid": "901097701",
    "manifest_id": "901097701",
    "test": true
  }
}
)