https://learn.microsoft.com/en-us/dotnet/api/microsoft.extensions.dependencyinjection.newtonsoftjsonmvcbuilderextensions.addnewtonsoftjson?view=aspnetcore-10.0
NewtonsoftJsonMvcBuilderExtensions.AddNewtonsoftJson Method...
Configures Newtonsoft.Json specific features such as input and output formatters.
method