how to get the access token and refresh token while sync the calendar of outlook in nodejs

To get the access token and refresh token while syncing the calendar of Outlook in Node.js, you can use the Microsoft Graph API and follow these steps:

1. Register your application with Microsoft Azure by creating an Azure AD tenant and registering your application with it.

2. Once you have registered your application, you can use the client ID and secret to obtain an access token and refresh token for the user.

3. Use the Microsoft Graph API to authenticate the user and obtain the access token and refresh token. You can use the following code to authenticate the user:

const msal = require('@azure/msal-node');

const REDIRECT_URI = 'http://localhost:3000/redirect';
const CLIENT_ID = '<your-client-id>';
const CLIENT_SECRET = '<your-client-secret>';
const SCOPES = ['https://graph.microsoft.com/.default'];

const pca = new msal.PublicClientApplication({
  auth: {
    clientId: CLIENT_ID,
    redirectUri: REDIRECT_URI,
    authority: 'https://login.microsoftonline.com/common',
  },
});

const authCodeUrlParameters = {
  scopes: SCOPES,
  redirectUri: REDIRECT_URI,
};

// Get the authorization URL
const authCodeUrl = await pca.getAuthCodeUrl(authCodeUrlParameters);

// Redirect the user to the authorization URL
res.redirect(authCodeUrl);

4. Once the user has authenticated, they will be redirected to the redirect URI you specified in the previous step. You can use the following code to exchange the authorization code for an access token and refresh token:

const authCode = req.query.code;

const tokenRequest = {
  code: authCode,
  scopes: SCOPES,
  redirectUri: REDIRECT_URI,
  clientSecret: CLIENT_SECRET,
};

const response = await pca.acquireTokenByCode(tokenRequest);
const accessToken = response.accessToken;
const refreshToken = response.refreshToken;

5. You can now use the access token and refresh token to sync the calendar of Outlook using the Microsoft Graph API. You can use the following code to get the events from the user's calendar:

const { Client } = require('@microsoft/microsoft-graph-client');

const client = Client.init({
  authProvider: (done) => {
    done(null, accessToken);
  },
});

const events = await client.api('/me/events').get();
console.log(events);

Note: Make sure to store the refresh token securely and use it to obtain a new access token as needed.