curl --request POST \
  --url https://api.example.test/custom_fields \
  --header 'Content-Type: application/json' \
  --data '
{
  "custom_field": {
    "key": null,
    "name": "<string>",
    "section_name": "<string>",
    "default_options": {},
    "default_component": "<string>",
    "applicable_model": "<string>",
    "organization_id": null
  }
}
'

import requests

url = "https://api.example.test/custom_fields"

payload = { "custom_field": {
        "key": None,
        "name": "<string>",
        "section_name": "<string>",
        "default_options": {},
        "default_component": "<string>",
        "applicable_model": "<string>",
        "organization_id": None
    } }
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({
    custom_field: {
      key: null,
      name: '<string>',
      section_name: '<string>',
      default_options: {},
      default_component: '<string>',
      applicable_model: '<string>',
      organization_id: null
    }
  })
};

fetch('https://api.example.test/custom_fields', 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/custom_fields",
  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([
    'custom_field' => [
        'key' => null,
        'name' => '<string>',
        'section_name' => '<string>',
        'default_options' => [
                
        ],
        'default_component' => '<string>',
        'applicable_model' => '<string>',
        'organization_id' => null
    ]
  ]),
  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.example.test/custom_fields"

	payload := strings.NewReader("{\n  \"custom_field\": {\n    \"key\": null,\n    \"name\": \"<string>\",\n    \"section_name\": \"<string>\",\n    \"default_options\": {},\n    \"default_component\": \"<string>\",\n    \"applicable_model\": \"<string>\",\n    \"organization_id\": null\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.example.test/custom_fields")
  .header("Content-Type", "application/json")
  .body("{\n  \"custom_field\": {\n    \"key\": null,\n    \"name\": \"<string>\",\n    \"section_name\": \"<string>\",\n    \"default_options\": {},\n    \"default_component\": \"<string>\",\n    \"applicable_model\": \"<string>\",\n    \"organization_id\": null\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.example.test/custom_fields")

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  \"custom_field\": {\n    \"key\": null,\n    \"name\": \"<string>\",\n    \"section_name\": \"<string>\",\n    \"default_options\": {},\n    \"default_component\": \"<string>\",\n    \"applicable_model\": \"<string>\",\n    \"organization_id\": null\n  }\n}"

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