我认为你的oauth2Client有问题，你没有请求用户授权。
试试我的样品，它应该开箱即用。

const fs = require('fs').promises;
const path = require('path');
const process = require('process');
const {authenticate} = require('@google-cloud/local-auth');
const {google} = require('googleapis');

// If modifying these scopes, delete token.json.
const SCOPES = ['https://www.googleapis.com/auth/calendar.readonly'];
// The file token.json stores the user's access and refresh tokens, and is
// created automatically when the authorization flow completes for the first
// time.
const TOKEN_PATH = path.join(process.cwd(), 'token.json');
const CREDENTIALS_PATH =  'C:\\Development\\FreeLance\\GoogleSamples\\Credentials\\CredWebEverything.json';

/**
 * Reads previously authorized credentials from the save file.
 *
 * @return {Promise<OAuth2Client|null>}
 */
async function loadSavedCredentialsIfExist() {
    try {
        const content = await fs.readFile(TOKEN_PATH);
        const credentials = JSON.parse(content);
        return google.auth.fromJSON(credentials);
    } catch (err) {
        return null;
    }
}

/**
 * Serializes credentials to a file compatible with GoogleAUth.fromJSON.
 *
 * @param {OAuth2Client} client
 * @return {Promise<void>}
 */
async function saveCredentials(client) {
    const content = await fs.readFile(CREDENTIALS_PATH);
    const keys = JSON.parse(content);
    const key = keys.installed || keys.web;
    const payload = JSON.stringify({
        type: 'authorized_user',
        client_id: key.client_id,
        client_secret: key.client_secret,
        refresh_token: client.credentials.refresh_token,
    });
    await fs.writeFile(TOKEN_PATH, payload);
}

/**
 * Load or request or authorization to call APIs.
 *
 */
async function authorize() {
    let client = await loadSavedCredentialsIfExist();
    if (client) {
        return client;
    }
    client = await authenticate({
        scopes: SCOPES,
        keyfilePath: CREDENTIALS_PATH,
    });
    if (client.credentials) {
        await saveCredentials(client);
    }
    return client;
}

/**
 * Lists the next 10 events on the user's primary calendar.
 * @param {google.auth.OAuth2} auth An authorized OAuth2 client.
 */
async function listEvents(auth) {
    const calendar = google.calendar({version: 'v3', auth});
    const res = await calendar.events.list({
        calendarId: 'primary',
        timeMin: new Date().toISOString(),
        maxResults: 10,
        singleEvents: true,
        orderBy: 'startTime',
    });
    const events = res.data.items;
    if (!events || events.length === 0) {
        console.log('No upcoming events found.');
        return;
    }
    console.log('Upcoming 10 events:');
    events.map((event, i) => {
        const start = event.start.dateTime || event.start.date;
        console.log(`${start} - ${event.summary}`);
    });
}

authorize().then(listEvents).catch(console.error);