curl --request POST \
  --url https://payments.magicblock.app/v1/spl/login \
  --header 'Content-Type: application/json' \
  --data '
{
  "pubkey": "Bt9oNR5cCtnfuMmXgWELd6q5i974PdEMQDUE55nBC57L",
  "challenge": "1234567890",
  "signature": "1234567890"
}
'

import requests

url = "https://payments.magicblock.app/v1/spl/login"

payload = {
    "pubkey": "Bt9oNR5cCtnfuMmXgWELd6q5i974PdEMQDUE55nBC57L",
    "challenge": "1234567890",
    "signature": "1234567890"
}
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({
    pubkey: 'Bt9oNR5cCtnfuMmXgWELd6q5i974PdEMQDUE55nBC57L',
    challenge: '1234567890',
    signature: '1234567890'
  })
};

fetch('https://payments.magicblock.app/v1/spl/login', 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://payments.magicblock.app/v1/spl/login",
  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([
    'pubkey' => 'Bt9oNR5cCtnfuMmXgWELd6q5i974PdEMQDUE55nBC57L',
    'challenge' => '1234567890',
    'signature' => '1234567890'
  ]),
  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://payments.magicblock.app/v1/spl/login"

	payload := strings.NewReader("{\n  \"pubkey\": \"Bt9oNR5cCtnfuMmXgWELd6q5i974PdEMQDUE55nBC57L\",\n  \"challenge\": \"1234567890\",\n  \"signature\": \"1234567890\"\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://payments.magicblock.app/v1/spl/login")
  .header("Content-Type", "application/json")
  .body("{\n  \"pubkey\": \"Bt9oNR5cCtnfuMmXgWELd6q5i974PdEMQDUE55nBC57L\",\n  \"challenge\": \"1234567890\",\n  \"signature\": \"1234567890\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://payments.magicblock.app/v1/spl/login")

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  \"pubkey\": \"Bt9oNR5cCtnfuMmXgWELd6q5i974PdEMQDUE55nBC57L\",\n  \"challenge\": \"1234567890\",\n  \"signature\": \"1234567890\"\n}"

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

{
  "token": "1234567890"
}