fetch('https://eudb.vim-adventures.com//php/level.php?level=4', {
  method: 'POST',
  headers: {
    "Authorization": "Basic MDl3YXR0cnlAZ21haWwuY29tOjA5V2hhdHJ1c3M/",
    "Origin": "https://vim-adventures.com",
    "Referer": "https://vim-adventures.com/",
    "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.121 Safari/537.36",
    "X-Token": "9e550f9198cd779b5c8ed220f7a4065809ae4804"
  }
})
.then(res => res.json())
.then(console.log);