Reset forgotten password: passwordreset.microsoftonline.com
Change your password on M365 portal: My Account >> security and privacy >> password
Password policy: your password must contain a minimum of 8 characters and it must contain at least three of the following: (1) a lowercase letter (2) an uppercase letter (3) a number (4) special characters, e.g. -, %, $, !. Your new password must also be different from your previous passwords.
After you have reset/changed your password, please do not forget to set your new password on ALL your devices (telephone, tablet, laptop) otherwise you can be locked out from your account.
Still have problems logging in? Contact firstname.lastname@example.org, or personally in room L204.