app/views/confirmable/confirmations/new.html.erb
<h2>Resend confirmation instructions</h2>
<%= form_for(resource, :as => resource_name, :url => confirmation_path(resource_name), :html => { :method => :post }) do |f| %>
<%= render partial: 'devise/shared/error_messages', resource: resource %>
<div><%= f.label :email %><br />
<%= f.email_field :email, :autofocus => true %></div>
<div><%= f.submit "Resend confirmation instructions" %></div>
<% end %>
<%= render "devise/shared/links" %>