I have set up a middleware where i take configuration from user(admin). The configuration which is taken from user is sql server connection, azure ad config, themes etc. After taking configuration i have shown user a button for restarting the application as below.

public class AzureAdSettingsMiddleware
{
    private readonly RequestDelegate _next;
    private readonly IWebHostEnvironment _webHostEnvironment;

    public AzureAdSettingsMiddleware(RequestDelegate next, IWebHostEnvironment webHostEnvironment)
    {
        _next = next;
        _webHostEnvironment = webHostEnvironment;
    }

    public async Task InvokeAsync(HttpContext context, IConfiguration configuration)
    {
        ApiDomainConfigurationModel apiDomainFileData = SettingsFileHelper.GetApiDomainFileData();
        DbConnectionDto dbConfigFileData = SettingsFileHelper.GetDbConfigFileData();
        AzureAdSettings adSettings = SettingsFileHelper.GetAzureAdSettingsFromFile();
        ThemeSettings themeConfig = SettingsFileHelper.GetThemeSettingFileData();

        dbConfigFileData = (dbConfigFileData != null && dbConfigFileData.ConnectionString != null) ? dbConfigFileData : null;
        apiDomainFileData = (apiDomainFileData != null && apiDomainFileData.BaseUrl != null) ? apiDomainFileData : null;


        if (apiDomainFileData == null || dbConfigFileData == null || adSettings == null || themeConfig == null)
        {
            if (!context.Request.Path.StartsWithSegments(UrlConstants.ApiDomainConfiguration) &&
                !context.Request.Path.StartsWithSegments(UrlConstants.AdConfiguration) &&
                !context.Request.Path.StartsWithSegments(UrlConstants.ThemeConfiguration) &&
                !context.Request.Path.StartsWithSegments(UrlConstants.DbConfiguration) &&
                !context.Request.Path.StartsWithSegments(UrlConstants.Instruction))
            {
                context.Response.Redirect(UrlConstants.Instruction);
                return;
            }
            else if (!context.Request.Path.StartsWithSegments(UrlConstants.Instruction))
            {
                if (apiDomainFileData == null)
                {
                    if (!context.Request.Path.StartsWithSegments(UrlConstants.ApiDomainConfiguration))
                    {
                        context.Response.Redirect(UrlConstants.ApiDomainConfiguration);
                        return;
                    }
                }
                else if (adSettings == null)
                {
                    if (!context.Request.Path.StartsWithSegments(UrlConstants.AdConfiguration))
                    {
                        context.Response.Redirect(UrlConstants.AdConfiguration);
                        return;
                    }
                }
                else if (themeConfig == null)
                {
                    if (!context.Request.Path.StartsWithSegments(UrlConstants.ThemeConfiguration))
                    {
                        context.Response.Redirect(UrlConstants.ThemeConfiguration);
                        return;
                    }
                }
                else if (dbConfigFileData == null)
                {
                    if (!context.Request.Path.StartsWithSegments(UrlConstants.DbConfiguration))
                    {
                        context.Response.Redirect(UrlConstants.DbConfiguration);
                        return;
                    }
                }
                
            }
           
        }
        else if (!context.Request.Path.StartsWithSegments(UrlConstants.SetupComplete))
        {
            configuration["SiteSettings:BaseUrl"] = apiDomainFileData.BaseUrl;
            var azureAdClientId = configuration["AzureAd:ClientId"];
            if (azureAdClientId != adSettings.ClientId)
            {
                if (!context.Request.Path.StartsWithSegments(UrlConstants.AdSetupComplete))
                {
                    context.Response.Headers.Append("X-Message",
                        "Your AD is set up. Please restart the application");
                    var redirectUrl = "/Settings/SetupComplete?redirected=true";
                    context.Response.Redirect(redirectUrl);
                    return;
                }
            }
            if (context.Request.Path.Equals("/"))
            {
                context.Response.Redirect("/Dashboard/Index");
                return;
            }
        }

        if (context.Request.Path.StartsWithSegments(UrlConstants.SetupComplete) &&
            context.Request.Method.Equals("POST", StringComparison.OrdinalIgnoreCase))
        {
            RestartApplication(context);
            return;
        }

        await _next(context);
    }

    private async void RestartApplication(HttpContext context)
    {
        string rootPath = _webHostEnvironment.ContentRootPath;
        string offlineFilePath = Path.Combine(rootPath, "app_offline.htm");

        if (!File.Exists(offlineFilePath))
        {
            File.WriteAllText(offlineFilePath, "<html><body><h1>Application is restarting...</h1></body></html>");
        }

        await Task.Delay(5000);
        if (File.Exists(offlineFilePath))
        {
            File.Delete(offlineFilePath);
        }

        using HttpClient httpClient = new HttpClient();
        httpClient.Timeout = TimeSpan.FromSeconds(10);

        try
        {
            var response =
                await httpClient.GetAsync($"{context.Request.Scheme}://{context.Request.Host}{UrlConstants.Home}");
            response.EnsureSuccessStatusCode();
        }
        catch (HttpRequestException ex)
        {
            Console.WriteLine("Request failed: " + ex.Message);
        }
        context.Response.Redirect(UrlConstants.Home);
    }

And this is my View for setup complete.

@{
    Layout = "_NewLayout";
    ViewData["Title"] = "AD Setup Complete";
    ViewData["HeaderTitle"] = "Configuration Completed.";
}


<div class="row">
    <div class="col title-md mt-4">
        You have successfully registered. Please restart the application.
    </div>
</div>

<div class="row">
    <div class="col">
        <form method="post">
            @Html.AntiForgeryToken()
            <button type="submit" id="restartAppButton" class="btn btn-primary">Restart App</button>
        </form>
    </div>
</div>

I have multiple projects but the main is web app where the app_offline.htm file is generated. The problem i am facing in the root this file app_offline.htm is generated, but restarting is not triggered. Any thoughts on that is appreciated.!