Using New Outlook on Windows for personal email, calendar, and contact management
https://support.google.com/mail/answer/7126229
Gmail users with a personal Google Account - Starting January 2025, the option to choose “Enable IMAP” or “Disable IMAP” won't be available. IMAP access is always turned on in Gmail, and your current connections to other email clients aren’t affected. You don’t need to take any action.
If you are still having problems adding your GMail IMAP account to New Outlook for Windows - Please try these instructions and describe any errors, or where it does not match what you are seeing.