Quote from site :
'''
This is something that’s strangely doesn’t seem to be that well documented and took me a while to figure out though in the end it’s pretty simple.
All that’s required is to add the following NuGet packages and an appsettings.json file.
Microsoft.Extensions.Configuration
Microsoft.Extensions.Configuration.FileExtensions
Microsoft.Extensions.Configuration.Json
'''
appsettings-json-in-net-core-console-app