I have added the following JSON object in the appsetting.json file.

 {
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*",

  "credentials": {
    "UserName": "Shubham",
    "Password": "code2night",
    "Email": "code2night@gmail.com"
  }
}

We will create a model class in which we will define properties with the same name as we have defined in our appsettings.json, Create a class inside the model folder 

    public class CredSettingsModel
    {
        public string UserName { get; set; }
        public string Password { get; set; }
        public string Email { get; set; }

    }

Go to Program.cs file and we will register our class by writing the below code.

 builder.Services.Configure<CredSettingsModel>(builder.Configuration.GetSection("credentials"));

Then we can inject it into our HomeController constructor using our IOptions instance.

using ConfigrationManager.Models;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Options;
using System.Diagnostics;

namespace ConfigrationManager.Controllers
{
    public class HomeController : Controller
    {
        private readonly ILogger<HomeController> _logger;
        protected readonly IConfiguration _configuration;
        private readonly CredSettingsModel _credSettingsModel;
        public HomeController(ILogger<HomeController> logger, IOptions<CredSettingsModel> options)
        {
            _logger = logger;
            _credSettingsModel = options.Value;
        }

        public IActionResult Index()
        {
            string UserName = _credSettingsModel.UserName;
            string Password = _credSettingsModel.Password;
            string Email = _credSettingsModel.Email;
            return View();
        }

    }
}

Run the project and see the output it will show the username which we mentioned in the appsetting.json file