PDF Reader Pro supports volume purchase on Microsoft Store. It applied to Windows 10 and Windows 10 Mobile.
Microsoft Store for Business, Please click Here.
Microsoft Store for Education, Please click Here.
Note: Before you sign up for Microsoft Store for Business or Microsoft Store for Education, you'll need an Azure Active Directory (AD) or Office 365 account for your organization, and you'll need to be the global administrator for your organization. If your organization is already using Azure AD, you can go ahead and sign up for Microsoft Store for Business or Microsoft Store for Education. If not, please create an Azure AD or Office 365 account and directory as part of the sign up process.
How to sign up on Microsoft Store? Get more information.