Non profit Office 365 - licensing questions

Hello everyone, 

We have a non profit customer and a terminal server and we configured a few years ago a Windows Server 2019 terminal server. 

For the moment, they use a Office 2019 Standard but we know that this kind of license can't be used on a terminal server.

Free business Basic licenses are used for Exchange/Sharepoint. 

I recently saw that Microsoft 365 Business Premium could be requested , I ordered it (for free up to 10 users) and I know that this product is elligible for terminal server (or Shared Computer Activation)

https://www.microsoft.com/en-us/nonprofits/microsoft-365-plans-pricing-grants

For the rest of the users what kind of license has to be ordered ? Can I mix the free Business Premium and Microsoft 365 Apps for Enterprise (3.20€/user) or do I have to order the same type of license (Premium = 4.20€/user) ? 

Or is there a "special Office license" for non profit enterprise on VLSC for non profit organisation ? 

Thanks in advance.