services.ConfigureRouting(setupAction => {
    setupAction.LowercaseUrls = true;
});

[Route("dashboard-settings")]
class DashboardSettings:Controller {
    public IActionResult Index() {
        // ...
    }
}

public class DashedRoutingConvention : IControllerModelConvention
 {

        public void Apply(ControllerModel controller)
        {
            var hasRouteAttributes = controller.Selectors.Any(selector =>
                                               selector.AttributeRouteModel != null);
            if (hasRouteAttributes)
            {
                // This controller manually defined some routes, so treat this
                // as an override and not apply the convention here.
                return;
            }

            foreach (var controllerAction in controller.Actions)
            {
                foreach (var selector in controllerAction.Selectors.Where(x => x.AttributeRouteModel == null))
                {
                    var template = new StringBuilder();

                    if (controllerAction.Controller.ControllerName != "Home")
                    {
                        template.Append(PascalToKebabCase(controller.ControllerName));
                    }



                    if (controllerAction.ActionName != "Index")
                    {
                        template.Append("/" + PascalToKebabCase(controllerAction.ActionName));
                    }

                    selector.AttributeRouteModel = new AttributeRouteModel()
                    {
                        Template = template.ToString()
                    };
                }
            }

        }

        public static string PascalToKebabCase(string value)
        {
            if (string.IsNullOrEmpty(value))
                return value;

            return Regex.Replace(
                value,
                "(?<!^)([A-Z][a-z]|(?<=[a-z])[A-Z])",
                "-$1",
                RegexOptions.Compiled)
                .Trim()
                .ToLower();
        }
}

public void ConfigureServices(IServiceCollection services)
{
    // Add framework services.
    services.AddMvc(options => options.Conventions.Add(new DashedRoutingConvention()));
}

foreach (var selector in controllerAction.Selectors
                                         .Where(x => x.AttributeRouteModel == null))