//...
.AddOpenIdConnect("oidc", options =>
                {
                    // ...
                    options.Events = new OpenIdConnectEvents
                    {
                        OnTokenValidated = async ctx =>
                        {
                          // how to access claims
                          var user = ctx.Principal;                    
                          var email = user.Claims.FirstOrDefault(claim => claim.Type == "email").Value;

                          // how to access services
                          var db = ctx.HttpContext.RequestServices.GetRequiredService<MyDb>();

                          // ....
                        }
                    };
                });

 var encryptedConverter = new ValueConverter<string, string>(
               convertToProviderExpression: v => v, // How to save it: Do nothing --> Save it normally in the DB
               convertFromProviderExpression: v => new string(v.Reverse().ToArray()) // How to report it: Show it encrypted to the user
            );

PM> Install-Package toastr

toastr.success("نمایش یک پیام - success", "عنوان");

toastr.options = {
            tapToDismiss: true,
            toastClass: 'toast',
            containerId: 'toast-container',
            debug: false,

            showMethod: 'fadeIn', //fadeIn, slideDown, and show are built into jQuery
            showDuration: 300,
            showEasing: 'swing', //swing and linear are built into jQuery
            onShown: undefined,
            hideMethod: 'fadeOut',
            hideDuration: 1000,
            hideEasing: 'swing',
            onHidden: undefined,

            extendedTimeOut: 1000,
            iconClasses: {
                error: 'toast-error',
                info: 'toast-info',
                success: 'toast-success',
                warning: 'toast-warning'
            },
            iconClass: 'toast-info',
            positionClass: 'toast-top-right',
            timeOut: 5000, // Set timeOut and extendedTimeOut to 0 to make it sticky
            titleClass: 'toast-title',
            messageClass: 'toast-message',
            target: 'body',
            closeHtml: '<button>&times;</button>',
            newestOnTop: true,
            preventDuplicates: false,
            progressBar: false
};

public class NotificationHub : Hub
{
        private readonly IProductService _productService;

        public NotificationHub(IProductService productService)
        {
            _productService = productService;
        }

        public void SendNotification()
        {
            Clients.Others.ShowNotification(_productService.GetLastProduct());
        }
}