Can't assign CustomComponent source to custom component (or) visible property

I'm trying to follow the example here for setting a CustomComponent source to a custom component class name. I downloaded the latest updates for Radzen. Is something missing now? I only see an option to choose a page name; not my custom class I added via Visual Studio Code.

Secondly, I want to toggle the visibility of this CustomComponent (it will be a spinner) but I don't see any Visible property of the CustomComponent either. The component doesn't look like the following example. Did something change here too?

I am building a Blazor server app.

Thanks, anyone!

You can set component name as expression and desired property as attribute:

PS: I've noticed second data-bind property button which will be corrected immediately.