CoHTTP

open Cohttp_lwt_unix
open Cohttp
open Lwt

let uri = Uri.of_string "http://blizzcmsv2.fixcore.fx/api/ApiAccount/user/5" in //this is my website url
let headers = Header.add_list (Header.init ()) [
  ("content-type", "multipart/form-data; boundary=---011000010111000001101001");
  ("x-api-key", "MYCODE@123"); //this is my Api key
  ("authorization", "Basic MYCREDENTIAL"); //this is my credential
] in

Client.call ~headers `GET uri //method
>>= fun (res, body_stream) ->
  (* Do stuff with the result *)