Instead of ‘login’ and ‘password’ use your credentials from https://app.dataforseo.com/api-access

# Instead of 'login' and 'password' use your credentials from https://app.dataforseo.com/api-access
login="login"
password="password"
cred="$(printf ${login}:${password} | base64)"
curl --location --request POST "https://api.dataforseo.com/v3/serp/{{low_se_name}}/{{low_se_type}}/live/html" \
--header "Authorization: Basic ${cred}" \
--header "Content-Type: application/json" \
--data-raw '[
    {
        "language_code": "en",
        "location_code": 2840
    }
]'

<?php
// You can download this file from here https://cdn.dataforseo.com/v3/examples/php/php_RestClient.zip
require('RestClient.php');
$api_url = 'https://api.dataforseo.com/';
try {
	// Instead of 'login' and 'password' use your credentials from https://app.dataforseo.com/api-access
	$client = new RestClient($api_url, null, 'login', 'password');
} catch (RestClientException $e) {
	echo "n";
	print "HTTP code: {$e->getHttpCode()}n";
	print "Error code: {$e->getCode()}n";
	print "Message: {$e->getMessage()}n";
	print  $e->getTraceAsString();
	echo "n";
	exit();
}
$post_array = array();
// You can set only one task at a time
$post_array[] = array(
	"language_code" => "en",
	"location_code" => 2840
);
try {
	// POST /v3/serp/{{low_se_name}}/{{low_se_type}}/live/html
	// in addition to '{{low_se_name}}' and '{{low_se_type}}' you can also set other search engine and type parameters
	// the full list of possible parameters is available in documentation
	$result = $client->post('/v3/serp/{{low_se_name}}/{{low_se_type}}/live/html', $post_array);
	print_r($result);
	// do something with post result
} catch (RestClientException $e) {
	echo "n";
	print "HTTP code: {$e->getHttpCode()}n";
	print "Error code: {$e->getCode()}n";
	print "Message: {$e->getMessage()}n";
	print  $e->getTraceAsString();
	echo "n";
}
$client = null;
?>

from client import RestClient
# You can download this file from here https://cdn.dataforseo.com/v3/examples/python/python_Client.zip
client = RestClient("login", "password")
post_data = dict()
# You can set only one task at a time
post_data[len(post_data)] = dict(
    language_code="en",
    location_code=2840
)
# POST POST /v3/serp/{{low_se_name}}/{{low_se_type}}/live/html
# in addition to '{{low_se_name}}' and '{{low_se_type}}' you can also set other search engine and type parameters
# the full list of possible parameters is available in documentation
response = client.post("/v3/serp/{{low_se_name}}/{{low_se_type}}/live/html", post_data)
# you can find the full list of the response codes here https://docs.dataforseo.com/v3/appendix/errors
if response["status_code"] == 20000:
    print(response)
    # do something with result
else:
    print("error. Code: %d Message: %s" % (response["status_code"], response["status_message"]))

const axios = require('axios');

axios({
    method: 'post',
    url: 'https://api.dataforseo.com/v3/serp/google/images/live/html',
    auth: {
        username: 'login',
        password: 'password'
    },
    data: [{
        "language_code": "en",
        "location_code": 2840
    }],
    headers: {
        'content-type': 'application/json'
    }
}).then(function (response) {
    var result = response['data']['tasks'];
    // Result data
    console.log(result);
}).catch(function (error) {
    console.log(error);
});

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Threading.Tasks;

namespace DataForSeoDemos
{
    public static partial class Demos
    {
        public static async Task serp_live_html()
        {
            var httpClient = new HttpClient
            {
                BaseAddress = new Uri("https://api.dataforseo.com/"),
                // Instead of 'login' and 'password' use your credentials from https://app.dataforseo.com/api-access
                //DefaultRequestHeaders = { Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(Encoding.ASCII.GetBytes("login:password"))) }
            };
            var postData = new List<object>();
            // You can set only one task at a time
            postData.Add(new
            {
                language_code = "en",
                location_code = 2840
            });
            // POST /v3/serp/{{low_se_name}}/{{low_se_type}}/live/html
            // in addition to '{{low_se_name}}' and '{{low_se_type}}' you can also set other search engine and type parameters
            // the full list of possible parameters is available in documentation
            var taskPostResponse = await httpClient.PostAsync("/v3/serp/{{low_se_name}}/{{low_se_type}}/live/html", new StringContent(JsonConvert.SerializeObject(postData)));
            var result = JsonConvert.DeserializeObject<dynamic>(await taskPostResponse.Content.ReadAsStringAsync());
            // you can find the full list of the response codes here https://docs.dataforseo.com/v3/appendix/errors
            if (result.status_code == 20000)
            {
                // do something with result
                Console.WriteLine(result);
            }
            else
                Console.WriteLine($"error. Code: {result.status_code} Message: {result.status_message}");
        }
    }
}

The above command returns JSON structured like this:

{
  "version": "0.1.20200130",
  "status_code": 20000,
  "status_message": "Ok.",
  "time": "7.7543 sec.",
  "cost": 0.003,
  "tasks_count": 1,
  "tasks_error": 0,
  "tasks": [
    {
      "id": "01301613-1535-0140-0000-c64ff6de0501",
      "status_code": 20000,
      "status_message": "Ok.",
      "time": "7.6463 sec.",
      "cost": 0.003,
      "result_count": 1,
      "path": [
        "v3",
        "serp",
        "{{low_se_name}}",
        "{{low_se_type_under}}",
        "live",
        "html"
      ],
      "data": {
        "api": "serp",
        "function": "live",
        "se": "{{low_se_name}}",
        "se_type": "{{low_se_type_under}}",
        "language_name": "English",
        "location_name": "United States",
        "tag": "tag1",
        "device": "desktop",
        "os": "windows"
      },
      "result": [
        {
          "keyword": null,
          "type": "organic",
          "se_domain": "google.com",
          "location_code": 2840,
          "language_code": "en",
          "datetime": "2020-01-30 14:13:54 +0000",
          "items_count": 1,
          "items": [
            {
              "page": 1,
              "date": "2020-01-30 14:13:54 +0000",
              "html": "<!doctype html><html><head></head></body></html>"
            }
          ]
        }
      ]
    }
  ]
}