ASP.NET Web Forms is a legacy programming framework that used a "drag and drop" designer--familiar to desktop application development--for web applications. Launched with .NET 1.0, the technology is now regarded as obsolete and not compatible with .NET Core.
Mobilize.Net, using its patented automated source code migration technology, has developed tooling to convert C#/ASP.NET Web Forms client code to HTML and CSS using the Angular web framework and Progress Kendo UI user interface elements. Application business logic is converted automatically to ASP.NET Core, the most up-to-date version of Microsoft's popular web server technology.
Check out the FAQ here.