Are you able to see the Devices option under assets, and consequently your devices? - If the answer to this is yes - then this is not a license problem.
You may be facing a permissions issue. Microsoft Defender for Endpoint administrator role or equivalent permissions Machine group administrator role or equivalent permissions If you are not able to see the Permissions option when in Endpoint, it could be due to permission issues. You can try checking your role and permission settings and adjust them accordingly. You can refer to the following documentation for more information: Create and manage machine groups in Microsoft Defender for Endpoint