email_forms/templates/optin.html.mustache
<form method="POST" action="{{ action }}">
<input type="hidden" name="token" value="{{ token }}" />
<input type="hidden" name="uselang" id="uselang" value="{{ uselang }}" />
<input type="hidden" name="contact_id" value="{{ contact_id }}" />
<input type="hidden" name="checksum" value="{{checksum}}" />
<input type="email" name="email" id="email" required value="{{ email }}" />
<p>{{ l10n "donate_interface-donor-opt_in_yes" }}</p>
<p class="small">{{{ l10n "donate_interface-donor-opt_in_explain" policy_url }}}</p>
<button type="submit" name="submit" id="continue" value="continue" >{{ l10n "donate_interface-continue" }}</button>
<button type="submit" name="submit" id="cancel" value="cancel" >{{ l10n "donate_interface-cancel" }}</button>
</form>