我正在尝试构建一个bing脚本，可以通过gmail帐户发送电子邮件，我的代码主要来自：https://ui.ads.microsoft.com/campaign/vnext/accounts/overview/expert?cid=19013943&uid=93024518
我已经尝试了我发现的常见修复方法，比如启用gmail api，授权相应的调用，currentl authorized是：
…/auth/gmail.send
…/auth/docs
…/auth/drive
…/auth/drive.scripts
…/auth/电子表格
…/auth/gmail.modify
…/auth/gmail.compose
https://mail.google.com/

function main() {
    var MailApp = new Bing();    
    const notificationEmail = '**my-email**';
    var email = [
        `To: ${notificationEmail}`,
        'Subject: Google Services script',
        '',
        `You script ran successfully ✓`
    ].join('\n');
    MailApp.sendEmail(email);  
}

class Bing{
    constructor() {
        this.credentials = {

            accessToken: '',
            clientId: '**my-client-id**',
            clientSecret: '**my-client-secret**',
            refreshToken: '**my-refresh-token**'

        };
        this.gmailApi = GoogleApis.createGmailService(this.credentials);
    }
    sendEmail(email) {
    }
}

// ^ Basic Copy+Paste from tutorial mentioned above ^
var GoogleApis;
(function (GoogleApis) {
  function createGmailService(credentials) {
    return createService("https://www.googleapis.com/discovery/v1/apis/gmail/v1/rest", credentials);
  }
  GoogleApis.createGmailService = createGmailService;

  // Creation logic based on https://developers.google.com/discovery/v1/using#usage-simple
  function createService(url, credentials) {
    var content = UrlFetchApp.fetch(url).getContentText();
    var discovery = JSON.parse(content);
    var baseUrl = discovery['rootUrl'] + discovery['servicePath'];
    var accessToken = getAccessToken(credentials);
    var service = build(discovery, {}, baseUrl, accessToken);
    return service;
  }

  function createNewMethod(method, baseUrl, accessToken) {
    return (urlParams, body) => {
      var urlPath = method.path;
      var queryArguments = [];
      for (var name in urlParams) {
        var paramConfg = method.parameters[name];
        if (!paramConfg) {
          throw `Unexpected url parameter ${name}`;
        }
        switch (paramConfg.location) {
          case 'path':
            urlPath = urlPath.replace('{' + name + '}', urlParams[name]);
            break;
          case 'query':
            queryArguments.push(`${name}=${urlParams[name]}`);
            break;
          default:
            throw `Unknown location ${paramConfg.location} for url parameter ${name}`;
        }
      }
      var url = baseUrl + urlPath;
      if (queryArguments.length > 0) {
        url += '?' + queryArguments.join('&');
      }
      var httpResponse = UrlFetchApp.fetch(url, { contentType: 'application/json', method: method.httpMethod, payload: JSON.stringify(body), headers: { Authorization: `Bearer ${accessToken}` }, muteHttpExceptions: true });
      var responseContent = httpResponse.getContentText();
      var responseCode = httpResponse.getResponseCode();
      var parsedResult;
      try {
        parsedResult = JSON.parse(responseContent);
      } catch (e) {
        parsedResult = false;
      }
      var response = new Response(parsedResult, responseContent, responseCode);
      if (responseCode >= 200 && responseCode <= 299) {
        return response;
      }
      throw response;
    }
  }

    function Response(result, body, status) {
    this.result = result;
    this.body = body;
    this.status = status;
  }
  Response.prototype.toString = function () {
    return this.body;
  }

  function build(discovery, collection, baseUrl, accessToken) {
    for (var name in discovery.resources) {
      var resource = discovery.resources[name];
      collection[name] = build(resource, {}, baseUrl, accessToken);
    }
    for (var name in discovery.methods) {
      var method = discovery.methods[name];
      collection[name] = createNewMethod(method, baseUrl, accessToken);
    }
    return collection;
  }

  function getAccessToken(credentials) {
    if (credentials.accessToken) {
      return credentials.accessToken;
    }
    var tokenResponse = UrlFetchApp.fetch('https://www.googleapis.com/oauth2/v4/token', { method: 'post', contentType: 'application/x-www-form-urlencoded', muteHttpExceptions: true, payload: { client_id: credentials.clientId, client_secret: credentials.clientSecret, refresh_token: credentials.refreshToken, grant_type: 'refresh_token' } });    
    var responseCode = tokenResponse.getResponseCode(); 
    var responseText = tokenResponse.getContentText(); 
    if (responseCode >= 200 && responseCode <= 299) {
      var accessToken = JSON.parse(responseText)['access_token'];
      return accessToken;
    }    
    throw responseText;  
  }
})(GoogleApis || (GoogleApis = {}));

class Base64 {
  static encode(input) {
    const keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
    let output = "";
    let chr1, chr2, chr3, enc1, enc2, enc3, enc4;
    var i = 0;
    input = this.utf8Encode(input);
    while (i < input.length) {
      chr1 = input.charCodeAt(i++);
      chr2 = input.charCodeAt(i++);
      chr3 = input.charCodeAt(i++);
      enc1 = chr1 >> 2;
      enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
      enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
      enc4 = chr3 & 63;
      if (isNaN(chr2)) {
        enc3 = enc4 = 64;
      }
      else if (isNaN(chr3)) {
        enc4 = 64;
      }
      output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2) + keyStr.charAt(enc3) + keyStr.charAt(enc4);
    }
    return output.replace(/\+/g, "-").replace(/\//g, "_").replace(/=+$/, "");
  }
  static utf8Encode(input) {
    input = input.replace(/\r\n/g, "\n");
    var utftext = "";
    for (var n = 0; n < input.length; n++) {
      var c = input.charCodeAt(n);
      if (c < 128) {
        utftext += String.fromCharCode(c);
      }
      else if ((c > 127) && (c < 2048)) {
        utftext += String.fromCharCode((c >> 6) | 192);
        utftext += String.fromCharCode((c & 63) | 128);
      }
      else {
        utftext += String.fromCharCode((c >> 12) | 224);
        utftext += String.fromCharCode(((c >> 6) & 63) | 128);
        utftext += String.fromCharCode((c & 63) | 128);
      }
    }
    return utftext;
  }
}

我使用本教程中的选项2从google获得了oauth2：https://docs.microsoft.com/en-us/advertising/scripts/examples/authenticating-with-google-services
作用域已正确启用，即…/auth/gmail.send
但我仍然得到以下错误：

{
"error": {
"code": 403,
"message": "Request had insufficient authentication scopes.",
"errors": [
{
"message": "Insufficient Permission",
"domain": "global",
"reason": "insufficientPermissions"
}
],
"status": "PERMISSION_DENIED"
}
}