Youtube Data API: The request cannot be completed because you have exceeded your quota

{
  "error": {
    "code": 403,
    "message": "The request cannot be completed because you have exceeded your \u003ca href=\"/youtube/v3/getting-started#quota\"\u003equota\u003c/a\u003e.",
    "errors": [{
      "message": "The request cannot be completed because you have exceeded your \u003ca href=\"/youtube/v3/getting-started#quota\"\u003equota\u003c/a\u003e.",
      "domain": "youtube.quota",
      "reason": "quotaExceeded"
    }]
  }
}