appsettings.json

{
  "Serilog": {
    "MinimumLevel": {
      "Default": "Information",
      "Override": {
        "Microsoft": "Warning",
        "System": "Warning"
      }
    },
    "WriteTo": [
      {
        "Name": "Console"
      },
      {
        "Name": "File",
        "Args": {
          "path": "log/log.txt",
          //"outputTemplate": "{Timestamp:o} [{Level:u3}] ({SourceContext}) {Message}{NewLine}{Exception}",
          "rollingInterval": "Day",
          "retainedFileCountLimit": 20
        }
      }
    ],
    "Enrich": [
      "FromLogContext",
      "WithMachineName"
    ],
    "Properties": {
      "Application": "AIMS"
    }
  }
}

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Serilog;

namespace serilog_mvc_demo
{
    public class Program
    {
        public static void Main(string[] args)
        {
            Log.Logger = new LoggerConfiguration()
                .Enrich.FromLogContext()
                .CreateLogger();

            CreateHostBuilder(args).Build().Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .UseSerilog((hosting, logerconfig)=>
                    logerconfig.ReadFrom.Configuration(hosting.Configuration))  
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    
                    webBuilder.UseStartup<Startup>();
                });
          
    }
}