curl --request POST \
  --url https://vicem.com/modules/addons/DomainsReseller/api/index.php/domains/{domain}/nameservers/modify \
  --header 'Content-Type: application/x-www-form-urlencoded' \
  --header 'token: <token>' \
  --header 'username: <username>' \
  --data nameserver=ns1.example.com \
  --data currentipaddress=192.0.2.1 \
  --data newipaddress=192.0.2.2

import requests

url = "https://vicem.com/modules/addons/DomainsReseller/api/index.php/domains/{domain}/nameservers/modify"

payload = {
    "nameserver": "ns1.example.com",
    "currentipaddress": "192.0.2.1",
    "newipaddress": "192.0.2.2"
}
headers = {
    "username": "<username>",
    "token": "<token>",
    "Content-Type": "application/x-www-form-urlencoded"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {
    username: '<username>',
    token: '<token>',
    'Content-Type': 'application/x-www-form-urlencoded'
  },
  body: new URLSearchParams({
    nameserver: 'ns1.example.com',
    currentipaddress: '192.0.2.1',
    newipaddress: '192.0.2.2'
  })
};

fetch('https://vicem.com/modules/addons/DomainsReseller/api/index.php/domains/{domain}/nameservers/modify', 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://vicem.com/modules/addons/DomainsReseller/api/index.php/domains/{domain}/nameservers/modify",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => "nameserver=ns1.example.com&currentipaddress=192.0.2.1&newipaddress=192.0.2.2",
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/x-www-form-urlencoded",
    "token: <token>",
    "username: <username>"
  ],
]);

$response = curl_exec($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://vicem.com/modules/addons/DomainsReseller/api/index.php/domains/{domain}/nameservers/modify"

	payload := strings.NewReader("nameserver=ns1.example.com&currentipaddress=192.0.2.1&newipaddress=192.0.2.2")

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

	req.Header.Add("username", "<username>")
	req.Header.Add("token", "<token>")
	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://vicem.com/modules/addons/DomainsReseller/api/index.php/domains/{domain}/nameservers/modify")
  .header("username", "<username>")
  .header("token", "<token>")
  .header("Content-Type", "application/x-www-form-urlencoded")
  .body("nameserver=ns1.example.com&currentipaddress=192.0.2.1&newipaddress=192.0.2.2")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://vicem.com/modules/addons/DomainsReseller/api/index.php/domains/{domain}/nameservers/modify")

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

request = Net::HTTP::Post.new(url)
request["username"] = '<username>'
request["token"] = '<token>'
request["Content-Type"] = 'application/x-www-form-urlencoded'
request.body = "nameserver=ns1.example.com&currentipaddress=192.0.2.1&newipaddress=192.0.2.2"

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

"success"

{
  "error": "Invalid API Token provided"
}

{
  "error": "Invalid API Token provided"
}

{
  "error": "Invalid API Token provided"
}

{
  "error": "Invalid API Token provided"
}