curl --request POST \
  --url https://accounts.livechat.com/v2/token \
  --header 'Content-Type: application/json' \
  --data '
{
  "grant_type": "code",
  "client_id": "0805e283233042b37f460ed8fbf22160",
  "client_secret": "secret",
  "redirect_uri": "https://my.app.com/callback",
  "code": "us-south1:test_tW5tQ-yBR2iQgGM6rWbz3w"
}
'

import requests

url = "https://accounts.livechat.com/v2/token"

payload = {
    "grant_type": "code",
    "client_id": "0805e283233042b37f460ed8fbf22160",
    "client_secret": "secret",
    "redirect_uri": "https://my.app.com/callback",
    "code": "us-south1:test_tW5tQ-yBR2iQgGM6rWbz3w"
}
headers = {"Content-Type": "application/json"}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    grant_type: 'code',
    client_id: '0805e283233042b37f460ed8fbf22160',
    client_secret: 'secret',
    redirect_uri: 'https://my.app.com/callback',
    code: 'us-south1:test_tW5tQ-yBR2iQgGM6rWbz3w'
  })
};

fetch('https://accounts.livechat.com/v2/token', 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://accounts.livechat.com/v2/token",
  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([
    'grant_type' => 'code',
    'client_id' => '0805e283233042b37f460ed8fbf22160',
    'client_secret' => 'secret',
    'redirect_uri' => 'https://my.app.com/callback',
    'code' => 'us-south1:test_tW5tQ-yBR2iQgGM6rWbz3w'
  ]),
  CURLOPT_HTTPHEADER => [
    "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://accounts.livechat.com/v2/token"

	payload := strings.NewReader("{\n  \"grant_type\": \"code\",\n  \"client_id\": \"0805e283233042b37f460ed8fbf22160\",\n  \"client_secret\": \"secret\",\n  \"redirect_uri\": \"https://my.app.com/callback\",\n  \"code\": \"us-south1:test_tW5tQ-yBR2iQgGM6rWbz3w\"\n}")

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

	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://accounts.livechat.com/v2/token")
  .header("Content-Type", "application/json")
  .body("{\n  \"grant_type\": \"code\",\n  \"client_id\": \"0805e283233042b37f460ed8fbf22160\",\n  \"client_secret\": \"secret\",\n  \"redirect_uri\": \"https://my.app.com/callback\",\n  \"code\": \"us-south1:test_tW5tQ-yBR2iQgGM6rWbz3w\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://accounts.livechat.com/v2/token")

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

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"grant_type\": \"code\",\n  \"client_id\": \"0805e283233042b37f460ed8fbf22160\",\n  \"client_secret\": \"secret\",\n  \"redirect_uri\": \"https://my.app.com/callback\",\n  \"code\": \"us-south1:test_tW5tQ-yBR2iQgGM6rWbz3w\"\n}"

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

{
  "access_token": "us-south1:test_tW5tQ-yBR2iQgGM6rWbz3w.lfVHLsxoJnrNJZ7JFZkYFwTEr2g-d3nPvt",
  "account_id": "496a94f2-cbbf-444e-a3cb-305b9f5f8cbb",
  "client_id": "0805e283233042b37f460ed8fbf22160",
  "expires_in": 28800,
  "organization_id": "b2185556-634c-4ecf-b4c9-bcf8b65bc853",
  "refresh_token": null,
  "scope": "accounts--my:rw accounts--all:ro",
  "token_type": "Bearer"
}

{
  "error": "unauthorized",
  "error_description": "The account is not authorized.",
  "request_id": "5903c51b-89f0-41a9-a25d-4f39af100353"
}

{
  "error": "access_denied",
  "sub_error": "insufficient_scope",
  "error_description": "The resource owner or authorization server denied the request.",
  "request_id": "5903c51b-89f0-41a9-a25d-4f39af100353"
}

{
  "error": "invalid_request",
  "error_description": "The request is missing a required parameter, includes an invalid parameter value, includes a parameter more than once, or is otherwise malformed.",
  "invalid_fields": {
    "email": "invalid email address"
  },
  "request_id": "5903c51b-89f0-41a9-a25d-4f39af100353"
}

{
  "error": "temporarily_unavailable",
  "error_description": "The server is currently unable to handle the request due to a temporary overloading or maintenance of the server.",
  "request_id": "5903c51b-89f0-41a9-a25d-4f39af100353"
}

{
  "error": "server_error",
  "error_description": "The server encountered an unexpected condition that prevented it from fulfilling the request.",
  "request_id": "5903c51b-89f0-41a9-a25d-4f39af100353"
}