erpnext/templates/emails/training_event.html

<h3>{{_("Training Event")}}</h3>
<p>{{ message }}</p>

<h4>{{_("Details")}}</h4>
{{_("Event Name")}}: <a href="{{ event_link }}">{{ name }}</a>
<br>{{_("Event Location")}}: {{ location }}
<br>{{_("Start Time")}}: {{ start_time }}
<br>{{_("End Time")}}: {{ end_time }}
<br>{{_("Attendance")}}: {{ attendance }}

<h4>{{_("Update Response")}}</h4>
{% if not self_study %}
<p>{{_("Please update your status for this training event")}}:</p>
<form action="{{ confirm_link }}"><input style="display:inline-block" type="submit" value="Confirm Attendance" /></form>   
<form action="{{ reject_link }}"><input style="display:inline-block" type="submit" value="Reject Invitation" /></form>
{% else %}
<p>{{_("Please confirm once you have completed your training")}}:</p>
<form action="{{ complete_link }}"><input style="display:inline-block" type="submit" value="Completed Training" /></form>
{% endif %}
<p>{{_("Thank you")}},<br>
{{ user_fullname }}</p>