There is no official cross platform desktop GUI solution for .NET core. There are third party efforts however, take a look at avalonia and eto.forms. Or altern

There is no official cross platform desktop GUI solution for .NET core. There are third party efforts however, take a look at avalonia and eto.forms. Or alternatively think of doing a web app in ASP.NET core. If you don’t need a bells and whistles SPA then ASP.NET core MVC is a very performant solution.