Convert MP4 to WAV for witai speech API

let express = require("express");
let request = require("request");
const ffmpeg = require("fluent-ffmpeg");
const fs = require("fs");
let track =
  "https://cdn.fbsbx.com/v/t59.3654-21/52113399_803146416702766_1003332990597595136_n.mp4/audioclip-1551778334000-1950.mp4?_nc_cat=105&_nc_ht=cdn.fbsbx.com&oh=07e065c73899d3dd825828f4ce019138&oe=5C80FE67"; //your path to source file

async function createFile(track) {
  new Promise((resolve, reject) => {
    ffmpeg(track)
      .toFormat("wav")
      .on("error", err => {
        console.log("An error occurred: " + err.message);
        reject();
      })
      .on("progress", progress => {
        // console.log(JSON.stringify(progress));
        console.log("Processing: " + progress.targetSize + " KB converted");
      })
      .on("end", () => {
        console.log("Processing finished !");
      })
      .save("./hello.wav")
      .on("end", () => {
        console.log("On provcessing final end Processing finished !");
        resolve();
      }); //path where you want to save your file
  });
}
async function convertAndFind() {
  await createFile(track);
  request(
    {
      url: "https://api.wit.ai/speech?v=20160526",
      method: "POST",
      headers: {
        "cache-control": "no-cache",
        "content-disposition": "attachment; filename=" + "hello",
        authorization: "Bearer UOM5JKJ77YK7IMUINQPRIG7MRVRTUFNE",
        "content-type": "audio/wav"
      },
      encoding: null,
      body: fs.createReadStream("./hello.wav")
    },
    (error, response, body) => {
      if (error) {
        console.log({ name: error });
      } else {
        console.log(JSON.parse(response.body.toString()));
      }
    }
  );
}
convertAndFind();

let app = express();

app.listen(8000);