Twitch Helix API: Invalid OAuth Token Error

API
2

Helix uses bearer you specified oauth

await fetch(`https://api.twitch.tv/helix/users?login=${login}`, {
  headers: {
    "Client-ID": this.apiData.clientId,
    Authorization: `OAuth ${this.apiData.clientSecret}`,
  },
});

should be

await fetch(`https://api.twitch.tv/helix/users?login=${login}`, {
  headers: {
    "Client-ID": this.apiData.clientId,
    Authorization: `Bearer ${this.apiData.clientSecret}`,
  },
});