Added the 'bootstrap_flash' helper into application.html.erb

app/views/layouts/application.html.erb

@@ -8,6 +8,7 @@
 <meta name="viewport" content="width=device-width, initial-scale=1"/></head>
 <body>
 <%= render partial: "elements/navbar" %>
+<%= bootstrap_flash %>
 
 
 <%= yield %>