Domain-joined systems must use Windows 11 Enterprise Edition 64-bit version.
Features such as Credential Guard use virtualization-based security to protect information that could be used in credential theft attacks if compromised. There are a number of system requirements that must be met in order for Credential Guard to be configured and enabled properly. Virtualization-based security and Credential Guard are only available with Windows 11 Enterprise 64-bit version.
How this relates to the STIG checklist: STIG vs SCAP benchmark.