app/views/devise/mailer/confirmation_instructions.html.erb
<p><%= t('.greeting', recipient: @resource.first_name.capitalize, default: "Welcome #{@resource.first_name.capitalize}!") %></p>
<p><%= t('.instruction', default: 'You can confirm your account email through the link below:') %></p>
<p><%= link_to t('.action', default: 'Confirm my account'),
confirmation_url(@resource, host: ENV['HOST_URL'], confirmation_token: @token, locale: I18n.locale) %></p>