I just downloaded the extension to Visual Studio 2022. I then ran the command line dotnet AspNetZeroRadTool.dll TestNamespace.TestObject.json
as noted above. I was informed that .Net Core 2.2.0 was not installed and it listed out the versions that I do have installed. So I downloaded .Net Core SDK 2.2.0 and ran the command again and it worked without issues. I think this was happening in the GUI as well, however, the error was caught and so it just created the entity.
So, for those having issue, please make sure you have .Net Core SDK 2.2.0 installed and it will work as expected.
In case some else comes across this before seeing the other support inquiry, this is what helped me with the errors I was facing. I forgot that npm packages needed to be restored first as well as yarn command ran. So please check this out.
I was attempting to look at the "public" MVC solution and came accross errors in the console which show the frontend-metronic.min.js file is missing. I've looked on GitHub as well and it seems AspNetZero has removed the files. I've logged into my GitHub account as well. I've attached screenshots showing what's missing.