Outlook IMAP in PHP

I'm trying to retrieve inbox mail using IMAP, but I'm encountering the following error. I've attached the code and error details below. Please advise.

$imapServer = "{outlook.office365.com:993/imap/ssl/novalidate-cert}INBOX"; 
    $username = '*************';
    $password = '*************';  // Use an App Password for security

   $imapStream = imap_open($imapServer, $username, $password, OP_READONLY, 0, ['DISABLE_AUTHENTICATOR' => 'GSSAPI']);

I'm getting this error:

A PHP Error was encountered

Severity: Warning

Message: imap_open(): Couldn't open stream {outlook.office365.com:993/imap/ssl/novalidate-cert}INBOX

Filename: controllers/Cron_Controller.php

Line Number: 39

Backtrace:

File: C:\xampp73\htdocs\WPS2.0_2025_03_04_1847\application\controllers\Cron_Controller.php
Line: 39
Function: imap_open

File: C:\xampp73\htdocs\WPS2.0_2025_03_04_1847\index.php
Line: 348
Function: require_once

A PHP Error was encountered

Severity: Notice

Message: Unknown: LOGIN failed. (errflg=1)

Filename: Unknown

Line Number: 0

Backtrace

Thanks & Regards

Kumaresan