request to api.wit.ai/speech

Question

I should receive text from audio, but server receive empty result. PS. audio converts in a buffer

const request = require('request-promise');
const fs = require(`fs`);
const apikey = KEY;

async function recognize(audio) {
  const body = fs.readFileSync(audio);
  const uri = `https://api.wit.ai/speech`
  const response = request.post({
    uri,
    headers: {
      'Authorization': `Bearer ` + apikey,
      'Content-Type': 'audio/ogg',
    },
    body
  }).then(res => {
    console.log(res)
  })
}

This is the response received:

{
  "entities": {},   
  "intents": [], 
  "text": "", 
  "traits": {} 
}