app/views/devise/mailer/confirmation_instructions.html.erb
<p><%= t "device_custom.mail.wellcom" %>
<%= @email %>!</p>
<p><%= t "device_custom.mail.wellcom_message" %></p>
<p><%= link_to t("device_custom.mail.wellcom_confirm"), confirmation_url(@resource, confirmation_token: @token) %></p>