ASP .Net Core localhost is currently unable to handle this request

I created an ASP.NET Core Project and chose an empty project rather than the default template. I use Visual Studio For Mac. I added a few NuGet packages, see image,
Here’s an image of my Startup.cs file, Lastly, an image of my Program.cs File When i run the project I get this error “localhost is currently unable to handle this request. Http Error 500”. Since I can’t configure IIS on a Mac (Unless there’s a way?) I can’t seem to figure out what’s causing this error. Maybe I’m missing something on the Startup.cs File? What might be cause?