我想使用taxjar计算2个邮政编码之间的运输费用。 我正在检查taxjar api文档，并且在请求中看到了运输费用。 但是我想计算从1到2的运输成本。 如果有人使用taxjar，请帮助我。

$order_taxes = $client->taxForOrder([
  'from_country' => 'US','from_zip' => '92093','from_state' => 'CA','from_city' => 'La Jolla','from_street' => '9500 Gilman Drive','to_country' => 'US','to_zip' => '90002','to_state' => 'CA','to_city' => 'Los Angeles','to_street' => '1335 E 103rd St','amount' => 15,'shipping' => 1.5,'nexus_addresses' => [
    [
      'id' => 'Main Location','country' => 'US','zip' => '92093','state' => 'CA','city' => 'La Jolla','street' => '9500 Gilman Drive',]
  ],'line_items' => [
    [
      'id' => '1','quantity' => 1,'product_tax_code' => '20010','unit_price' => 15,'discount' => 0
    ]
  ]
]);