Click the Sign in link in the top right
In the login box, click Sign in with Microsoft Account button in left column
Upon being redirected to Office 365 login, proceed with using your Office 365 credentials
Approve the Multifactor authentication if applicable
You may be presented with a permissions request screen, you will have to click accept.
Welcome to Upic Answer Center.
**Note: If you do not have an Office 365 account, you can still login via the email and password form after clicking sign in.