curl --request PUT \
  --url https://api.example.test/invoice_items/{invoice_item_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "invoice_item": {
    "value": 123,
    "active": true,
    "sku": "<string>",
    "stockable": true,
    "tax_attributes": {
      "kop_id": 123,
      "uom_id": 123,
      "kop_key": "<string>",
      "uom_key": "<string>",
      "tax_rate": 123,
      "tax_type": "<string>",
      "tax_amount": null,
      "factor_type": "<string>",
      "rate_or_fee": "<string>",
      "rate_or_fee_id": 123,
      "kop_description": "<string>",
      "uom_description": "<string>"
    },
    "invoice_item_locations_location_ids": [
      123
    ]
  }
}
'

import requests

url = "https://api.example.test/invoice_items/{invoice_item_id}"

payload = { "invoice_item": {
        "value": 123,
        "active": True,
        "sku": "<string>",
        "stockable": True,
        "tax_attributes": {
            "kop_id": 123,
            "uom_id": 123,
            "kop_key": "<string>",
            "uom_key": "<string>",
            "tax_rate": 123,
            "tax_type": "<string>",
            "tax_amount": None,
            "factor_type": "<string>",
            "rate_or_fee": "<string>",
            "rate_or_fee_id": 123,
            "kop_description": "<string>",
            "uom_description": "<string>"
        },
        "invoice_item_locations_location_ids": [123]
    } }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'PUT',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    invoice_item: {
      value: 123,
      active: true,
      sku: '<string>',
      stockable: true,
      tax_attributes: {
        kop_id: 123,
        uom_id: 123,
        kop_key: '<string>',
        uom_key: '<string>',
        tax_rate: 123,
        tax_type: '<string>',
        tax_amount: null,
        factor_type: '<string>',
        rate_or_fee: '<string>',
        rate_or_fee_id: 123,
        kop_description: '<string>',
        uom_description: '<string>'
      },
      invoice_item_locations_location_ids: [123]
    }
  })
};

fetch('https://api.example.test/invoice_items/{invoice_item_id}', 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.example.test/invoice_items/{invoice_item_id}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PUT",
  CURLOPT_POSTFIELDS => json_encode([
    'invoice_item' => [
        'value' => 123,
        'active' => true,
        'sku' => '<string>',
        'stockable' => true,
        'tax_attributes' => [
                'kop_id' => 123,
                'uom_id' => 123,
                'kop_key' => '<string>',
                'uom_key' => '<string>',
                'tax_rate' => 123,
                'tax_type' => '<string>',
                'tax_amount' => null,
                'factor_type' => '<string>',
                'rate_or_fee' => '<string>',
                'rate_or_fee_id' => 123,
                'kop_description' => '<string>',
                'uom_description' => '<string>'
        ],
        'invoice_item_locations_location_ids' => [
                123
        ]
    ]
  ]),
  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.example.test/invoice_items/{invoice_item_id}"

	payload := strings.NewReader("{\n  \"invoice_item\": {\n    \"value\": 123,\n    \"active\": true,\n    \"sku\": \"<string>\",\n    \"stockable\": true,\n    \"tax_attributes\": {\n      \"kop_id\": 123,\n      \"uom_id\": 123,\n      \"kop_key\": \"<string>\",\n      \"uom_key\": \"<string>\",\n      \"tax_rate\": 123,\n      \"tax_type\": \"<string>\",\n      \"tax_amount\": null,\n      \"factor_type\": \"<string>\",\n      \"rate_or_fee\": \"<string>\",\n      \"rate_or_fee_id\": 123,\n      \"kop_description\": \"<string>\",\n      \"uom_description\": \"<string>\"\n    },\n    \"invoice_item_locations_location_ids\": [\n      123\n    ]\n  }\n}")

	req, _ := http.NewRequest("PUT", 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.put("https://api.example.test/invoice_items/{invoice_item_id}")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"invoice_item\": {\n    \"value\": 123,\n    \"active\": true,\n    \"sku\": \"<string>\",\n    \"stockable\": true,\n    \"tax_attributes\": {\n      \"kop_id\": 123,\n      \"uom_id\": 123,\n      \"kop_key\": \"<string>\",\n      \"uom_key\": \"<string>\",\n      \"tax_rate\": 123,\n      \"tax_type\": \"<string>\",\n      \"tax_amount\": null,\n      \"factor_type\": \"<string>\",\n      \"rate_or_fee\": \"<string>\",\n      \"rate_or_fee_id\": 123,\n      \"kop_description\": \"<string>\",\n      \"uom_description\": \"<string>\"\n    },\n    \"invoice_item_locations_location_ids\": [\n      123\n    ]\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.example.test/invoice_items/{invoice_item_id}")

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

request = Net::HTTP::Put.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"invoice_item\": {\n    \"value\": 123,\n    \"active\": true,\n    \"sku\": \"<string>\",\n    \"stockable\": true,\n    \"tax_attributes\": {\n      \"kop_id\": 123,\n      \"uom_id\": 123,\n      \"kop_key\": \"<string>\",\n      \"uom_key\": \"<string>\",\n      \"tax_rate\": 123,\n      \"tax_type\": \"<string>\",\n      \"tax_amount\": null,\n      \"factor_type\": \"<string>\",\n      \"rate_or_fee\": \"<string>\",\n      \"rate_or_fee_id\": 123,\n      \"kop_description\": \"<string>\",\n      \"uom_description\": \"<string>\"\n    },\n    \"invoice_item_locations_location_ids\": [\n      123\n    ]\n  }\n}"

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

{
  "invoice_item": {
    "id": 123,
    "value": 123,
    "organization_id": 123,
    "active": true,
    "stock_total": 123,
    "stockable": true,
    "sku": "<string>",
    "on_locations": "<string>",
    "links": {
      "invoice_item_locations": "<string>"
    },
    "invoice_item_locations_location_ids": [
      123
    ],
    "accounting_type": "<string>",
    "tax_attributes": {
      "kop_id": 123,
      "uom_id": 123,
      "kop_key": "<string>",
      "uom_key": "<string>",
      "tax_rate": 123,
      "tax_type": "<string>",
      "tax_amount": null,
      "factor_type": "<string>",
      "rate_or_fee": "<string>",
      "rate_or_fee_id": 123,
      "kop_description": "<string>",
      "uom_description": "<string>"
    }
  }
}