You connect a personal Microsoft account (Outlook.com, Hotmail, Live) by signing in with Microsoft. A password is not possible here: Microsoft does not allow that.
- Click Connect a calendar and enter your address.
- Click Sign in with Microsoft and give access to your calendar.
Microsoft itself sends attendees a message with every change and does not let you turn that off. If you change an appointment with others, we first ask whether you want to continue.
A work account (Microsoft 365)?
That is not possible yet. The administrator of your organisation must approve this once first; that option comes later.