access env var in dotnet core

appsettings.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Debug",
      "System": "Information",
      "Microsoft": "Information"
    }
  },
  "Jwt": {
    "Key": "veryVerySecretKey",
    "Issuer": "auth_server_brx"
  }
}

appsettings.{enviroment}.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Debug",
      "System": "Information",
      "Microsoft": "Information"
    }
  },
  "Jwt": {
    "Key": "veryVerySecretKey",
    "Issuer": "auth_server_brx"
  }
}

Startup.cs

public Startup(IConfiguration configuration)
{
    Configuration = configuration;
    StaticConfig = configuration;
}

public static IConfiguration Env { get; private set; }

// to use simply call the static member from anywher in the app
// Startup.Env["Jwt:issuer"]

Startup.csharp

public Startup(IConfiguration configuration)
{
    Configuration = configuration;
    StaticConfig = configuration;
}

public static IConfiguration Env { get; private set; }

// to use simply call the static member from anywher in the app
// Startup.Env["Jwt:issuer"]