curl --request PUT \
  --url https://api.fintoc.com/v2/entities/{entity_id}/onboardings/{id}/documents/{slot_key} \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: multipart/form-data' \
  --form file=@example-file

import requests

url = "https://api.fintoc.com/v2/entities/{entity_id}/onboardings/{id}/documents/{slot_key}"

files = { "file": ("example-file", open("example-file", "rb")) }
headers = {"Authorization": "<api-key>"}

response = requests.put(url, files=files, headers=headers)

print(response.text)

const form = new FormData();
form.append('file', '<string>');

const options = {method: 'PUT', headers: {Authorization: '<api-key>'}};

options.body = form;

fetch('https://api.fintoc.com/v2/entities/{entity_id}/onboardings/{id}/documents/{slot_key}', 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.fintoc.com/v2/entities/{entity_id}/onboardings/{id}/documents/{slot_key}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PUT",
  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--",
  CURLOPT_HTTPHEADER => [
    "Authorization: <api-key>",
    "Content-Type: multipart/form-data"
  ],
]);

$response = curl_exec($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.fintoc.com/v2/entities/{entity_id}/onboardings/{id}/documents/{slot_key}"

	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--")

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

	req.Header.Add("Authorization", "<api-key>")

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

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

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.put("https://api.fintoc.com/v2/entities/{entity_id}/onboardings/{id}/documents/{slot_key}")
  .header("Authorization", "<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--")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.fintoc.com/v2/entities/{entity_id}/onboardings/{id}/documents/{slot_key}")

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

request = Net::HTTP::Put.new(url)
request["Authorization"] = '<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--"

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

{
  "id": "onbprc_0ujsswThIGTUYm2K8FjOOfXtY1K",
  "object": "onboarding",
  "entity_id": "ent_8anBwgZktbZH6ydyHa6Tm0eM",
  "status": "in_progress",
  "source": "api",
  "submitted_at": null,
  "reviewed_at": null,
  "submittable": false,
  "data": {
    "company_information": {
      "legal_name": "Acme SA de CV"
    }
  },
  "legal_representatives": [],
  "shareholders": [],
  "documents": [
    {
      "slot_key": "proof_of_address",
      "status": "uploaded"
    }
  ]
}

{
  "error": {
    "type": "authentication_error",
    "code": "invalid_api_key",
    "message": "Invalid API Key: invalid-*oken"
  }
}

{
  "error": {
    "type": "invalid_request_error",
    "code": "missing_resource",
    "param": "id",
    "message": "No such onboarding: onbprc_0ujsswThIGTUYm2K8FjOOfXtY1K",
    "doc_url": "https://docs.fintoc.com/reference/errors"
  }
}

{
  "error": {
    "type": "invalid_request_error",
    "code": "unknown_document_slot",
    "param": "slot_key",
    "message": "No such document slot: nonexistent_slot",
    "doc_url": "https://docs.fintoc.com/reference/errors"
  }
}