app/views/user_mailer/confirmation_instructions.text.erb
<%= t 'devise.mailer.confirmation_instructions.title' %>
===
<%= t @resource.approved? ? 'devise.mailer.confirmation_instructions.explanation' : 'devise.mailer.confirmation_instructions.explanation_when_pending', host: site_hostname %>
=> <%= confirmation_url(@resource, confirmation_token: @token, redirect_to_app: @resource.created_by_application ? 'true' : nil) %>
<%= strip_tags(t('devise.mailer.confirmation_instructions.extra_html', terms_path: about_more_url, policy_path: terms_url)) %>
=> <%= about_more_url %>
=> <%= terms_url %>