silverlight is not supported in Visual studio 2019 so if you can open the project in visual studio it is not silverlight. You could also open the csproj file with notepad and look for the project type guid. For silverlight it is Silverlight {A1591282-1198-4647-A2B1-27E5FF5F6F3B}
You can find a list of the project types here
https://www.codeproject.com/reference/720512/list-of-visual-studio-project-type-guids