Hi @PauloMatos , To use the Work/School account option, you will need to have an Azure Active Directory (AAD) subscription.
The Azure AD Free tier includes the Work/School account option, so you can use this option with the Azure AD Free tier.
However, if you want to use more advanced features such as single sign-on or multi-factor authentication, you will need to upgrade to the Azure AD P1 or P2 tiers.
You can learn more about the different Azure AD tiers and their features here: https://azure.microsoft.com/en-us/pricing/details/active-directory/
I hope this helps! Let me know if you have any other questions.
If this answer helped you please mark it as "Verified" so other users can reference it.
Thank you,
James