Initialization Script - press Go button to initialize event templates
// src/actions/events/init.php - event templates initialization script
$request = new \HubSpot\Client\Crm\Timeline\Model\TimelineEventTemplateCreateRequest();
$request->setName('Event Template Name');
$request->setHeaderTemplate('Header Template');
$request->setDetailTemplate('Detail Template');
$request->setObjectType('Object Type');
$hubSpot->crm()->timeline()->templatesApi()
->create('HubSpot Application ID', $request);