app/views/devise/mailer/confirmation_instructions.html.erb
<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html charset=UTF-8">
</head>
<body>
<% if @resource.name.present? %>
<p>Welcome <%= @resource.name %>!</p>
<% else %>
<p>Welcome!</p>
<% end %>
<p>We're so happy that you're joining us on PlanningAlerts.</p>
<p>Please confirm your account email by clicking the link below:</p>
<p><%= link_to "Confirm account", confirmation_url(@resource, confirmation_token: @token) %></p>
<p>Didn't request this email? Then you can safely ignore it.</p>
</body>
</html>