appsettings.json

{
  "ConnectionStrings": {
    "UnitTestConnection": "Server=(localdb)\\mssqllocaldb;Database=EfCore.TestSupport-Test;Trusted_Connection=True;MultipleActiveResultSets=true",
    "PostgreSqlConnection": "Host=127.0.0.1;Port=5432;Database=Test-Test;Username=postgres;Password=LetMeIn",
    "BookOrderConnection": "Data Source=(localdb)\\mssqllocaldb;Initial Catalog=EfCore.TestSupport-Test_ComparerBooksAndOrders;Integrated Security=True;MultipleActiveResultSets=True"
  },
  "MyInt": 1,
  "MyObject": {
    "MyInnerInt":  2
  } 
}