email placeholder to remind users which address to check for their code

frontend/pweb/lib/pages/2fa/prompt.dart

@@ -1,5 +1,9 @@
 import 'package:flutter/material.dart';
 
+import 'package:provider/provider.dart';
+
+import 'package:pweb/providers/two_factor.dart';
+
 import 'package:pweb/generated/i18n/app_localizations.dart';
 
 
@@ -8,7 +12,9 @@ class TwoFactorPromptText extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) => Text(
-    AppLocalizations.of(context)!.twoFactorPrompt,
+    AppLocalizations.of(context)!.twoFactorPrompt(
+      context.watch<TwoFactorProvider>().pendingLogin?.destination ?? '',
+    ),
     style: Theme.of(context).textTheme.bodyLarge,
     textAlign: TextAlign.center,
   );