Do it by
Sign-in yourself in https://myaccount.microsoft.com/
Click the "My sign-ins" in the left-edge menu
Your recent active sign-in history is displayed
For detail, also refers to Microsoft's newest document. (eg. search keywords "Microsoft365 recent activity" and read the Microsoft Support in that page.)
If you also want to change your password, please read this QA, ignoring the URL told in that document.