Microsoft’s modern authentication methods.

I got this from Microsoft through outlook and it doesn’t single out anything, can anyone confirm it doesn’t apply to Calendly? “

What do you need to do?

If you are receiving this email, you are currently using an email or calendar app that uses a less secure authentication method to connect to your Outlook.com email account. You will need to upgrade your third-party mail and calendar app to a version which supports modern authentication methods.”