You got it, that's how I would do it in a CBV. I use FBVs:

python
def my_view(request):
  response = HttpResponse(status=204)
  response['HX-Trigger'] = 'myCustomEvent'
  return response

def html_response(request):
  response = render(request, 'my_templage.html', {'context': ''})
  response['HX-Trigger'] = 'myCustomEvent'
  return response