How to change the Lockout configuration

The Lockout settings are set with the settings configured in ASP.NET Identity.
Those options are used to define, for example, the TimeSpan a user is locked out for when a lockout occurs or the number of failed access attempts allowed before a user is locked out.

The documentation about the LockoutOptions in ASP.NET Core Identity is available here:
https://docs.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.identity.lockoutoptions

Reading configuration from an external config file

A better way to achieve this is to read configuration from configuration sources as settings files, environment variables, command-line arguments. For a complete list of the default configuration sources used by the default configuration providers, and how you can customize it, see the related ASP.NET Core documentation:
https://docs.microsoft.com/en-us/aspnet/core/fundamentals/configuration/

Using the appsettings.{Environment}.json settings files, for example appsettings.json, appsettings.Production.json and appsettings.Development.json, will allow you to specify different settings depending on the environment and transform the configuration section when you deploy it.

To do this, add a Configuration property in the Startup class:

public IConfiguration Configuration { get; }

In order to initialize the Configuration, set the property in the constructor like this:

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

Then, bind configuration with this code that reads it from the configuration file:

services.Configure<IdentityOptions>(options =>
{
    Configuration.GetSection("IdentityOptions").Bind(options);
});

Finally, create a file called appsettings.json with this configuration in json:

{  
  "IdentityOptions": {
    "Lockout": {
      "AllowedForNewUsers": true,
      "DefaultLockoutTimeSpan ": "00:05:00",
      "MaxFailedAccessAttempts ": 5
    }
  }
}

Summary

You just learned how to configure the Lockout settings from an appsettings.json file.