"error": { "status": 401, "message": "No token provided" }, On clicking the fetch_url link, following content being displayed

Context: I am new on the technology hence on developing my first project Music Master, for accessing the details of artist i have to use developer.spotify.com

The following is the code snippet:

const BASE_URL = 'https://api.spotify.com/v1/search?';
    const FETCH_URL = `${BASE_URL}q=${this.state.query}&type=artist&limit=1`;
    console.log('FETCH_URL', FETCH_URL);
    fetch('FETCH_URL', {
        method:'GET',
        headers: {
            'Accept': 'application/json',
            "Authorization": "Bearer BQAuzRQntApSOi_2gTlydxGPPY10waidioQkY53QKQSbUUsNrsZ8Tjl1jmema_P3dfV9lGAVuJmgzhDopTi632A_kyXhDchV_pLKf_2ot28ru9vCdFCbpPtVopwFRTuUA_8dAvQHogFlJPBhd9VQhJD0PSBFf4NZdPbl-PTcyTCvRVf84Is2d6mFeTRKAXmPTMU"              }
    })
    .then(response => response.json())
    .then(json => {
        const artist = json.artists.items[0];
        console.log('artist', artist);
        this.setState({artist});
    });

After the execution of code, i am receiving error:

{
 "error": {
 "status": 401,
 "message": "No token provided"
 }
}

When i use the curl command in terminal:

curl -X "GET" "https://api.spotify.com/v1/search? 
q=this.state.query&type=artist&limit=1" -H "Accept: application/json" -H "Content- 
Type: application/json" -H "Authorization: Bearer
QAuzRQntApSOi_2gTlydxGPPY10waidio 
QkY53QKQSbUUsNrsZ8Tjl1jmema_P3dfV9lGAVuJmgzhDopTi632A_k 
yXhDchV_pLKf_2ot28ru9vCdFCbpPtVopwFRTuUA_8dAvQHogFlJPBhd9VQhJD0PSBFf4NZdPbl- 
PTcyTCvRVf84Is2d6mFeTRKAXmPTMU"

I am receiving a proper formatted output in terminal:

{
  "artists" : {
  "href" : "https://api.spotify.com/v1/search? 
  query=this.state.query&type=artist&offset=0&limit=1",
  "items" : [ {
  "external_urls" : {
    "spotify" : "https://open.spotify.com/artist/0DpQjnQLcu01O2o6lqCPiL"
  },
  "followers" : {
    "href" : null,
    "total" : 2751
  },
  "genres" : [ "ambient post-rock", "blackgaze", "canadian experimental" ],
  "href" : "https://api.spotify.com/v1/artists/0DpQjnQLcu01O2o6lqCPiL",
  "id" : "0DpQjnQLcu01O2o6lqCPiL",
  "images" : [ {
    "height" : 640,
    "url" : "https://i.scdn.co/image/ab6761610000e5eb932ea1420ceae35a2ef4f61d",
    "width" : 640
  }, {
    "height" : 320,
    "url" : "https://i.scdn.co/image/ab67616100005174932ea1420ceae35a2ef4f61d",
    "width" : 320
  }, {
    "height" : 160,
    "url" : "https://i.scdn.co/image/ab6761610000f178932ea1420ceae35a2ef4f61d",
    "width" : 160
  } ],
  "name" : "Thisquietarmy",
  "popularity" : 4,
  "type" : "artist",
  "uri" : "spotify:artist:0DpQjnQLcu01O2o6lqCPiL"
} ],
"limit" : 1,
"next" : "https://api.spotify.com/v1/search?query=this.state.query&type=artist&offset=1&limit=1",
"offset" : 0,
"previous" : null,
"total" : 6
}

Please help me, i am not able to understand where i am going wrong.