You have a Microsoft Exchange organization that uses an SMTP address space of contoso.com.
Several users use their contoso.com email address for self-service sign-up to Azure Active Directory (Azure AD).
You gain global administrator privileges to the Azure AD tenant that contains the self-signed users.
You need to prevent the users from creating user accounts in the contoso.com Azure AD tenant for self-service sign-up to Microsoft 365 services.
Which PowerShell cmdlet should you run?