Here, you'll see all the login attempts that were made to access your account. For successful logins, check the IP address and country associated with it by clicking that entry.

If no other sign-in option is added to your Microsoft account, then the only way to sign in to your account is by using the Microsoft Authenticator app. But you do not have access to the app.

If a device you previously used is lost, stolen, or compromised with malware, it could access your Microsoft account. Navigate to your Microsoft account, select Devices, and click Remove device.