curl --request POST \
  --url https://api.relayapp.im/v1/attachments \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Length: <content-length>' \
  --header 'Content-Type: application/octet-stream' \
  --data '"<string>"'

import requests

url = "https://api.relayapp.im/v1/attachments"

payload = "<string>"
headers = {
    "Content-Length": "<content-length>",
    "Authorization": "Bearer <token>",
    "Content-Type": "application/octet-stream"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {
    'Content-Length': '<content-length>',
    Authorization: 'Bearer <token>',
    'Content-Type': 'application/octet-stream'
  },
  body: JSON.stringify('<string>')
};

fetch('https://api.relayapp.im/v1/attachments', 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.relayapp.im/v1/attachments",
  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('<string>'),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Length: <content-length>",
    "Content-Type: application/octet-stream"
  ],
]);

$response = curl_exec($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.relayapp.im/v1/attachments"

	payload := strings.NewReader("\"<string>\"")

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

	req.Header.Add("Content-Length", "<content-length>")
	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/octet-stream")

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

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

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.relayapp.im/v1/attachments")
  .header("Content-Length", "<content-length>")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/octet-stream")
  .body("\"<string>\"")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.relayapp.im/v1/attachments")

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

request = Net::HTTP::Post.new(url)
request["Content-Length"] = '<content-length>'
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/octet-stream'
request.body = "\"<string>\""

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

{
  "attachment": {
    "id": "att_01KXGWNZFR",
    "url": "<string>",
    "content_type": "image/png",
    "size_bytes": 123
  }
}

{
  "error": {
    "code": "invalid_request",
    "message": "conversation_id is required"
  }
}

{
  "error": {
    "code": "invalid_request",
    "message": "conversation_id is required"
  }
}

{
  "error": {
    "code": "invalid_request",
    "message": "conversation_id is required"
  }
}