Hello Minh,
Thank you for providing the details.
Since the purchased Windows GGWA – Windows 11 Home (Edu) licenses appear in the Microsoft 365 Admin Center but the product displays "No key required", there is currently no activation key available from the Admin Center that can be used to activate the devices.
Because this license was purchased through the CSP program, the activation and fulfillment method for the specific SKU must be confirmed by your CSP provider. I recommend contacting your CSP partner and requesting verification of the activation method associated with the purchased GGWA entitlement.
If the CSP partner is unable to locate activation guidance or activation assets for the SKU, they should open a support request with Microsoft and provide the tenant information, order details, SKU information, and a screenshot of the "No key required" message so Microsoft can review the entitlement and provide the official activation guidance.
At this point, the information available does not indicate a product key that can be retrieved from the Microsoft 365 Admin Center, so activation cannot be completed using the Admin Center alone.
If this information helps clarify the verification process, please consider marking this response as Accepted Answer. This helps other community members find useful information when facing similar questions.
Kind regards,