In the “Create a New ASP.NET Core Web Application” window shown next, select .NET Core as the runtime and ASP.NET Core 3.1 (or later) from the drop-down list at the top.

When working with ASP.NET Core or ASP.NET Core MVC 5 you no longer need a web.config file. However, using a web.config file is perfectly valid if you’re hosting your application in IIS.

In ASP.NET MVC (just "MVC' from here on in), configuration is handled through a combination of the web.config file, the Global.asax file, and the classes in the files in the Startup folder. In ASP.NET ...

The Practical Client Integrating Blazor into Existing ASP.NET Core Applications If you want to add server-side Blazor to your existing ASP.NET Core applications, you can. There's not much to it, ...