curl --request POST \
  --url https://gobl.dev/v0/sign \
  --header 'Content-Type: application/json' \
  --data '
{
  "data": "<unknown>",
  "template": "<unknown>",
  "privatekey": {
    "kty": "EC",
    "crv": "P-256",
    "alg": "ES256",
    "use": "sig",
    "kid": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "x": "<string>",
    "y": "<string>",
    "d": "<string>"
  },
  "type": "<string>",
  "envelop": true
}
'

import requests

url = "https://gobl.dev/v0/sign"

payload = {
    "data": "<unknown>",
    "template": "<unknown>",
    "privatekey": {
        "kty": "EC",
        "crv": "P-256",
        "alg": "ES256",
        "use": "sig",
        "kid": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "x": "<string>",
        "y": "<string>",
        "d": "<string>"
    },
    "type": "<string>",
    "envelop": True
}
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({
    data: '<unknown>',
    template: '<unknown>',
    privatekey: {
      kty: 'EC',
      crv: 'P-256',
      alg: 'ES256',
      use: 'sig',
      kid: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
      x: '<string>',
      y: '<string>',
      d: '<string>'
    },
    type: '<string>',
    envelop: true
  })
};

fetch('https://gobl.dev/v0/sign', 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://gobl.dev/v0/sign",
  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([
    'data' => '<unknown>',
    'template' => '<unknown>',
    'privatekey' => [
        'kty' => 'EC',
        'crv' => 'P-256',
        'alg' => 'ES256',
        'use' => 'sig',
        'kid' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
        'x' => '<string>',
        'y' => '<string>',
        'd' => '<string>'
    ],
    'type' => '<string>',
    'envelop' => true
  ]),
  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://gobl.dev/v0/sign"

	payload := strings.NewReader("{\n  \"data\": \"<unknown>\",\n  \"template\": \"<unknown>\",\n  \"privatekey\": {\n    \"kty\": \"EC\",\n    \"crv\": \"P-256\",\n    \"alg\": \"ES256\",\n    \"use\": \"sig\",\n    \"kid\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n    \"x\": \"<string>\",\n    \"y\": \"<string>\",\n    \"d\": \"<string>\"\n  },\n  \"type\": \"<string>\",\n  \"envelop\": true\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://gobl.dev/v0/sign")
  .header("Content-Type", "application/json")
  .body("{\n  \"data\": \"<unknown>\",\n  \"template\": \"<unknown>\",\n  \"privatekey\": {\n    \"kty\": \"EC\",\n    \"crv\": \"P-256\",\n    \"alg\": \"ES256\",\n    \"use\": \"sig\",\n    \"kid\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n    \"x\": \"<string>\",\n    \"y\": \"<string>\",\n    \"d\": \"<string>\"\n  },\n  \"type\": \"<string>\",\n  \"envelop\": true\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://gobl.dev/v0/sign")

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  \"data\": \"<unknown>\",\n  \"template\": \"<unknown>\",\n  \"privatekey\": {\n    \"kty\": \"EC\",\n    \"crv\": \"P-256\",\n    \"alg\": \"ES256\",\n    \"use\": \"sig\",\n    \"kid\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n    \"x\": \"<string>\",\n    \"y\": \"<string>\",\n    \"d\": \"<string>\"\n  },\n  \"type\": \"<string>\",\n  \"envelop\": true\n}"

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

{
  "code": 422,
  "key": "<string>",
  "message": "<string>",
  "faults": [
    {
      "properties": [
        "<string>"
      ],
      "description": "<string>"
    }
  ]
}

{
  "code": 422,
  "key": "<string>",
  "message": "<string>",
  "faults": [
    {
      "properties": [
        "<string>"
      ],
      "description": "<string>"
    }
  ]
}