Licensing Office in own virtualized environment

Question

Hello,

We have a customer who is managing his own hardware on-premises with their VDI Infrastructure. The hardware is properly licensed with Windows Server Datacenter. They have Windows CALs and RDS CALs for users.

The virtualization is made using Citrix XenApp. They publish via a Terminal Server a Shared Full Desktop for the users.

They want also to use Office suite with they current virtual infrastructure and they want to use SCA (shared computer activation).

I know that they need to acquire Office/Microsoft 365 plans that allow SCA for each user (ex. M365 Business Premium, Office 365 E3, Microsoft 365 E3/E5).

The question is that taking into account the fact that the virtualization is done using Citrix XenApp, is it enough to buy the Office/Microsoft 365 plans allowing SCA for each user? Or they need to buy supplementary Microsoft products that are related to VDI rights (ex. Windows 10/11 Enterprise VDA)?

Thanks