I have a new Client Side (Hosted) app. It has a Client, Server and Shared project (default template). I installed the Radzen components per your website. However, neither the
_content/Radzen.Blazor/css/default.css
or
_content/Radzen.Blazor/Radzen.Blazor.js"
are functional. I put the required usings in _Imports.razor. I am using Nuget package with version 2.4.4. The components are recognized, but not the styling etc.