title: Axios post, missing grant type
body: <p>Getting data: <code>{ error: 'invalid_request', error_description: 'Missing grant type' } }</code></p>
  
  <p>Content-Type is correct, not sure what is wrong</p>
  
  <pre><code>return axiosInstance({
    method: 'post',
    url: axiosInstance.defaults.baseURL + '/oauth/token',
    data: {
      "grant_type": "vapi_key",
      key: api_key
    },
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded'
    }
  })
  </code></pre>
  
  <p>Edit: This is called via NodeJS</p>