Trigger Emails/Handlers on Webform submissions update
The below code is untested but should point you in the right direction.

// Get a handler.
$webform_submission = WebformSubmission::load(WEBFORM_ID)
$handlers = $webform_submission-&gt;getWebform()-&gt;getHandlers();
$handler = $handlers[HANDLER_ID];

// Invoke submit form.
@see \Drupal\webform\Plugin\WebformHandlerInterface::submitForm
$form = []; // Might need to get the $form.
$form_state = new FormState(); // Might need to be build the form state.
$handler-&gt;submitForm($form, $form_state, $webform_submission);


@see \Drupal\webform\Entity\Webform::invokeHandlers

@see \Drupal\webform\Entity\WebformSubmission::invokeWebformHandlers