curl --request POST \
  --url https://thirdparty-sandbox.staging.qonto.co/register/registrations/{registrationId}/files \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --header 'Qonto-Partner-Id: <api-key>' \
  --form file='@example-file' \
  --form file_type=organization-deposit-certificate \
  --form stakeholder_id=a3818b4d-4240-4098-bae4-87124b5add31

import requests

url = "https://thirdparty-sandbox.staging.qonto.co/register/registrations/{registrationId}/files"

files = { "file": ("example-file", open("example-file", "rb")) }
payload = {
    "file_type": "organization-deposit-certificate",
    "stakeholder_id": "a3818b4d-4240-4098-bae4-87124b5add31"
}
headers = {
    "Authorization": "Bearer <token>",
    "Qonto-Partner-Id": "<api-key>"
}

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

print(response.text)

const form = new FormData();
form.append('file', '<string>');
form.append('file_type', 'organization-deposit-certificate');
form.append('stakeholder_id', 'a3818b4d-4240-4098-bae4-87124b5add31');

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Qonto-Partner-Id': '<api-key>'}
};

options.body = form;

fetch('https://thirdparty-sandbox.staging.qonto.co/register/registrations/{registrationId}/files', 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://thirdparty-sandbox.staging.qonto.co/register/registrations/{registrationId}/files",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file_type\"\r\n\r\norganization-deposit-certificate\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"stakeholder_id\"\r\n\r\na3818b4d-4240-4098-bae4-87124b5add31\r\n-----011000010111000001101001--",
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: multipart/form-data",
    "Qonto-Partner-Id: <api-key>"
  ],
]);

$response = curl_exec($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://thirdparty-sandbox.staging.qonto.co/register/registrations/{registrationId}/files"

	payload := strings.NewReader("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file_type\"\r\n\r\norganization-deposit-certificate\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"stakeholder_id\"\r\n\r\na3818b4d-4240-4098-bae4-87124b5add31\r\n-----011000010111000001101001--")

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

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Qonto-Partner-Id", "<api-key>")

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

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

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://thirdparty-sandbox.staging.qonto.co/register/registrations/{registrationId}/files")
  .header("Authorization", "Bearer <token>")
  .header("Qonto-Partner-Id", "<api-key>")
  .body("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file_type\"\r\n\r\norganization-deposit-certificate\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"stakeholder_id\"\r\n\r\na3818b4d-4240-4098-bae4-87124b5add31\r\n-----011000010111000001101001--")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://thirdparty-sandbox.staging.qonto.co/register/registrations/{registrationId}/files")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Qonto-Partner-Id"] = '<api-key>'
request.body = "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file_type\"\r\n\r\norganization-deposit-certificate\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"stakeholder_id\"\r\n\r\na3818b4d-4240-4098-bae4-87124b5add31\r\n-----011000010111000001101001--"

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

{
  "registration_file": {
    "id": "d7344200-97d7-44b7-8fc5-9e5fb2f8831b",
    "filename": "document.pdf",
    "filesize_bytes": 981723,
    "url": "https://example-s3-url",
    "created_at": "2021-08-17T12:31:32.689Z",
    "file_type": "organization-deposit-certificate",
    "stakeholder_id": "<string>"
  }
}

{
  "errors": [
    {
      "code": "<string>",
      "detail": "<string>",
      "source": {
        "pointer": "<string>"
      }
    }
  ]
}

{
  "errors": [
    {
      "code": "unauthorized",
      "detail": "You must authenticate to perform API requests"
    }
  ]
}

{
  "errors": [
    {
      "code": "not_found",
      "detail": "The record identified by <uuid> could not be found."
    }
  ]
}

{
  "errors": [
    {
      "code": "<error-code>",
      "detail": "<relevant-detail>",
      "source": {
        "pointer": "<ie /data/attributes/attr_name>"
      }
    }
  ]
}