curl --request POST \
  --url https://api.globalwebindex.com/v3/query/audience_wave_counts \
  --header 'Content-Type: application/json' \
  --data '
{
  "expression": {},
  "locations": [
    "s2_1",
    "s2_44"
  ],
  "waves": [
    "q1_2019",
    "q2_2019",
    "q3_2019",
    "q4_2019"
  ]
}
'

import requests

url = "https://api.globalwebindex.com/v3/query/audience_wave_counts"

payload = {
    "expression": {},
    "locations": ["s2_1", "s2_44"],
    "waves": ["q1_2019", "q2_2019", "q3_2019", "q4_2019"]
}
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({
    expression: {},
    locations: ['s2_1', 's2_44'],
    waves: ['q1_2019', 'q2_2019', 'q3_2019', 'q4_2019']
  })
};

fetch('https://api.globalwebindex.com/v3/query/audience_wave_counts', 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.globalwebindex.com/v3/query/audience_wave_counts",
  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([
    'expression' => [
        
    ],
    'locations' => [
        's2_1',
        's2_44'
    ],
    'waves' => [
        'q1_2019',
        'q2_2019',
        'q3_2019',
        'q4_2019'
    ]
  ]),
  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://api.globalwebindex.com/v3/query/audience_wave_counts"

	payload := strings.NewReader("{\n  \"expression\": {},\n  \"locations\": [\n    \"s2_1\",\n    \"s2_44\"\n  ],\n  \"waves\": [\n    \"q1_2019\",\n    \"q2_2019\",\n    \"q3_2019\",\n    \"q4_2019\"\n  ]\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://api.globalwebindex.com/v3/query/audience_wave_counts")
  .header("Content-Type", "application/json")
  .body("{\n  \"expression\": {},\n  \"locations\": [\n    \"s2_1\",\n    \"s2_44\"\n  ],\n  \"waves\": [\n    \"q1_2019\",\n    \"q2_2019\",\n    \"q3_2019\",\n    \"q4_2019\"\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.globalwebindex.com/v3/query/audience_wave_counts")

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  \"expression\": {},\n  \"locations\": [\n    \"s2_1\",\n    \"s2_44\"\n  ],\n  \"waves\": [\n    \"q1_2019\",\n    \"q2_2019\",\n    \"q3_2019\",\n    \"q4_2019\"\n  ]\n}"

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

{
  "base_size": 123,
  "base_sample": 123,
  "audience_sample": 123,
  "audience_size": 123,
  "audience_percentage": 123,
  "per_wave_count": [
    {
      "code": "q2_2019",
      "name": "Q2 2019",
      "sample": 10,
      "percentage": 0.3
    }
  ]
}

{
  "error": "some_error",
  "error_type": "empty_expression",
  "code": 400,
  "message": "Message readable by customer."
}

{
  "error": "some_error",
  "error_type": "empty_expression",
  "code": 400,
  "message": "Message readable by customer."
}

{
  "error": "some_error",
  "error_type": "empty_expression",
  "code": 403,
  "meta": {
    "forbidden_codes": {
      "questions": [
        {
          "code": "q2",
          "datapoints": [
            "q1_1"
          ],
          "origin": "question"
        }
      ],
      "locations": [
        "s2_44"
      ],
      "waves": [
        "q1_2019"
      ]
    }
  }
}