curl --request POST \
  --url https://api.sonderplan.com/v2/billable-item \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "name": "Aspera Upload",
  "currency": "AUD",
  "id": 92834,
  "description": "Upload to Aspera (per TB)",
  "unit_name": "Terabyte",
  "buy_cost": "10.00",
  "sell_cost": "20.00",
  "taxes": [
    {
      "id": 3247,
      "name": "GST",
      "rate": "10.00",
      "total": "151.00"
    }
  ],
  "custom_fields": [
    {
      "id": 7823,
      "name": "Type",
      "value": "Video Editing",
      "value_id": 8973,
      "update_key": "2_1_7823"
    }
  ]
}
'

import requests

url = "https://api.sonderplan.com/v2/billable-item"

payload = {
    "name": "Aspera Upload",
    "currency": "AUD",
    "id": 92834,
    "description": "Upload to Aspera (per TB)",
    "unit_name": "Terabyte",
    "buy_cost": "10.00",
    "sell_cost": "20.00",
    "taxes": [
        {
            "id": 3247,
            "name": "GST",
            "rate": "10.00",
            "total": "151.00"
        }
    ],
    "custom_fields": [
        {
            "id": 7823,
            "name": "Type",
            "value": "Video Editing",
            "value_id": 8973,
            "update_key": "2_1_7823"
        }
    ]
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    name: 'Aspera Upload',
    currency: 'AUD',
    id: 92834,
    description: 'Upload to Aspera (per TB)',
    unit_name: 'Terabyte',
    buy_cost: '10.00',
    sell_cost: '20.00',
    taxes: [{id: 3247, name: 'GST', rate: '10.00', total: '151.00'}],
    custom_fields: [
      {
        id: 7823,
        name: 'Type',
        value: 'Video Editing',
        value_id: 8973,
        update_key: '2_1_7823'
      }
    ]
  })
};

fetch('https://api.sonderplan.com/v2/billable-item', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.sonderplan.com/v2/billable-item",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'name' => 'Aspera Upload',
    'currency' => 'AUD',
    'id' => 92834,
    'description' => 'Upload to Aspera (per TB)',
    'unit_name' => 'Terabyte',
    'buy_cost' => '10.00',
    'sell_cost' => '20.00',
    'taxes' => [
        [
                'id' => 3247,
                'name' => 'GST',
                'rate' => '10.00',
                'total' => '151.00'
        ]
    ],
    'custom_fields' => [
        [
                'id' => 7823,
                'name' => 'Type',
                'value' => 'Video Editing',
                'value_id' => 8973,
                'update_key' => '2_1_7823'
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.sonderplan.com/v2/billable-item"

	payload := strings.NewReader("{\n  \"name\": \"Aspera Upload\",\n  \"currency\": \"AUD\",\n  \"id\": 92834,\n  \"description\": \"Upload to Aspera (per TB)\",\n  \"unit_name\": \"Terabyte\",\n  \"buy_cost\": \"10.00\",\n  \"sell_cost\": \"20.00\",\n  \"taxes\": [\n    {\n      \"id\": 3247,\n      \"name\": \"GST\",\n      \"rate\": \"10.00\",\n      \"total\": \"151.00\"\n    }\n  ],\n  \"custom_fields\": [\n    {\n      \"id\": 7823,\n      \"name\": \"Type\",\n      \"value\": \"Video Editing\",\n      \"value_id\": 8973,\n      \"update_key\": \"2_1_7823\"\n    }\n  ]\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.sonderplan.com/v2/billable-item")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"name\": \"Aspera Upload\",\n  \"currency\": \"AUD\",\n  \"id\": 92834,\n  \"description\": \"Upload to Aspera (per TB)\",\n  \"unit_name\": \"Terabyte\",\n  \"buy_cost\": \"10.00\",\n  \"sell_cost\": \"20.00\",\n  \"taxes\": [\n    {\n      \"id\": 3247,\n      \"name\": \"GST\",\n      \"rate\": \"10.00\",\n      \"total\": \"151.00\"\n    }\n  ],\n  \"custom_fields\": [\n    {\n      \"id\": 7823,\n      \"name\": \"Type\",\n      \"value\": \"Video Editing\",\n      \"value_id\": 8973,\n      \"update_key\": \"2_1_7823\"\n    }\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.sonderplan.com/v2/billable-item")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"name\": \"Aspera Upload\",\n  \"currency\": \"AUD\",\n  \"id\": 92834,\n  \"description\": \"Upload to Aspera (per TB)\",\n  \"unit_name\": \"Terabyte\",\n  \"buy_cost\": \"10.00\",\n  \"sell_cost\": \"20.00\",\n  \"taxes\": [\n    {\n      \"id\": 3247,\n      \"name\": \"GST\",\n      \"rate\": \"10.00\",\n      \"total\": \"151.00\"\n    }\n  ],\n  \"custom_fields\": [\n    {\n      \"id\": 7823,\n      \"name\": \"Type\",\n      \"value\": \"Video Editing\",\n      \"value_id\": 8973,\n      \"update_key\": \"2_1_7823\"\n    }\n  ]\n}"

response = http.request(request)
puts response.read_body

{
  "success": {
    "id": 1
  }
}

{
  "error": {
    "code": "404",
    "message": "Requested resource was not found"
  }
}