Serilog Add environment variable value

appsettings.Development.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Debug",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "Serilog": {
    "LevelSwitches": {
      "$controlSwitch": "Debug"
    },
    "WriteTo": [
      {
        "Name": "Seq",
        "Args": {
          "serverUrl": "http://localhost:5431",
          "apiKey": "<Your_Seq_API_Key>",
          "controlLevelSwitch": "$controlSwitch"
        }
      },
      {
        "Name": "Elasticsearch",
        "Args": {
          "nodeUris": "http://localhost:9200;http://remote-pc:9200",
          "indexFormat": "custom-index-{0:yyyy-MM}",
//          "templateName": "myCustomTemplate",
//          "typeName": "myCustomLogEventType",
//          "pipelineName": "myCustomPipelineName",
          "batchPostingLimit": 50,
          "batchAction": "Create",
          "period": 2,
          "inlineFields": true,
          "restrictedToMinimumLevel": "Debug",
//          "bufferBaseFilename":  "C:/Temp/docker-elk-serilog-web-buffer",
//          "bufferFileSizeLimitBytes": 5242880,
//          "bufferLogShippingInterval": 5000,
//          "bufferRetainedInvalidPayloadsLimitBytes": 5000,
//          "bufferFileCountLimit": 31,
//          "connectionGlobalHeaders" :"Authorization=Bearer SOME-TOKEN;OtherHeader=OTHER-HEADER-VALUE",
//          "connectionTimeout": 5,
//          "emitEventFailure": "WriteToSelfLog",
//          "queueSizeLimit": "100000",
          "autoRegisterTemplate": true,
          "autoRegisterTemplateVersion": "ESv2",
//          "overwriteTemplate": false,
          "registerTemplateFailure": "IndexAnyway",
          "deadLetterIndexName": "deadletter-{0:yyyy-MM}",
//          "numberOfShards: 20,
//          "numberOfReplicas": 10,
//          "templateCustomSettings": [{ "index.mapping.total_fields.limit": "10000000" } ],
//          "formatProvider": "My.Namespace.MyFormatProvider, My.Assembly.Name",
//          "connection": "My.Namespace.MyConnection, My.Assembly.Name",
//          "serializer": "My.Namespace.MySerializer, My.Assembly.Name",
//          "connectionPool": "My.Namespace.MyConnectionPool, My.Assembly.Name",
//          "customFormatter": "My.Namespace.MyCustomFormatter, My.Assembly.Name",
//          "customDurableFormatter": "My.Namespace.MyCustomDurableFormatter, My.Assembly.Name",
//          "failureSink": "My.Namespace.MyFailureSink, My.Assembly.Name"
        }
      },
      {
        "Name": "Console",
        "Args": {
          "outputTemplate": "[{Timestamp:HH:mm:ss} {Level:u3}] {Message:lj} <s:{SourceContext}>{NewLine}{Exception}",
          "controlLevelSwitch": "$controlSwitch"
        }
      }
    ]
  }
}

Program.cs

using System;
using System.Reflection;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Hosting;
using Serilog;
using Serilog.Events;
using Serilog.Exceptions;

/*
<PackageReference Include="Serilog.Enrichers.Environment" Version="2.2.0" />
<PackageReference Include="Serilog.Exceptions" Version="7.0.0" />
<PackageReference Include="Serilog.AspNetCore" Version="4.0.0" />


<PackageReference Include="Serilog.Sinks.Seq" Version="5.0.0" />
or
<PackageReference Include="Serilog.Sinks.Elasticsearch" Version="8.4.1" />
*/

namespace SerilogInWebApiSample
{
    public class Program
    {
        public static int Main(string[] args)
        {
            Log.Logger = new LoggerConfiguration()
                .MinimumLevel.Override("Microsoft", LogEventLevel.Information)
                .Enrich.FromLogContext()
                .WriteTo.Console()
                .CreateBootstrapLogger();

            try
            {
                Log.Information("Starting web host");
                CreateHostBuilder(args).Build().Run();
                return 0;
            }
            catch (Exception ex)
            {
                Log.Fatal($"Failed to start {Assembly.GetExecutingAssembly().GetName().Name}, Host terminated unexpectedly.", ex);
                return 1;
            }
            finally
            {
                Log.CloseAndFlush();
            }
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .UseSerilog((context, services, configuration) =>
                {
                    var imageVersion = Assembly.GetAssembly(typeof(Program))
                        .GetCustomAttribute<AssemblyInformationalVersionAttribute>()
                        .InformationalVersion;
                    
                    //var environment = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");
                    configuration
                        .ReadFrom.Configuration(context.Configuration)
                        .ReadFrom.Services(services)
                        .Enrich.WithMachineName()     // in Serilog.Enrichers.Environment
                        .Enrich.WithEnvironmentName() // in Serilog.Enrichers.Environment
                        .Enrich.WithProperty("Application", context.HostingEnvironment.ApplicationName)
                        //.Enrich.WithProperty("Environment", context.HostingEnvironment.EnvironmentName)
                        //.Enrich.WithProperty("environment_env", environment)
                        .Enrich.WithProperty("Version", imageVersion)
                        .Enrich.FromLogContext()
                        .Enrich.WithExceptionDetails(); // in Serilog.Exceptions
                })
                .ConfigureWebHostDefaults(webBuilder => { webBuilder.UseStartup<Startup>(); });
    }
}