There are several possible causes for your problem accessing Microsoft 365:

• You have lost your password Microsoft 365 → ask for a new password (you must be authenticated on the site), it will be sent to you by email within minutes;
• It's been a long time since you went through the QuIdAM procedure. So your license has probably not been activated yet → follow the QuIdAM password reset procedure (even if you have to re-enter your current password) to activate your license automatically. An information email will confirm the success of the activation procedure;
• You are neither an active staff member nor a student who is regularly enrolled in the current year. You therefore do not meet the administrative conditions to benefit from the license.

Info Microsoft 365 (pdf)