Is there any example of utter_custom_json() method?

Thanks Jitesh, I tried both of them. But not sure what the JSON payload or the YML format should be for Quick Replies - Messenger Platform - Documentation - Facebook for Developers.

I tried several different formats, this is one of them: https://gist.githubusercontent.com/Jasmin25/6bb30a2c52903dbc33935360696cc178/raw/911ed562bb11b3cfe430ffc2488fa3c6c4c25a7f/domain.yml

But I get following error:

rasa_1_8564a5b6e7c6 | 2019-06-10 14:01:40 ERROR    rasa.core.nlg.template  - Failed to fill utterance template '{'custom': {'message': {'quick_replies': [{'content_type': 'text', 'image_url': 'http://example.com/img/red.png', 'payload': '/start_subscription', 'title': 'Start'}, {'content_type': 'text', 'image_url': 'http://example.com/img/red.png', 'payload': '/stop_subscription', 'title': 'Stop'}], 'text': 'Here is a quick reply!'}}}'. Tried to replace 'text' but could not find a value for it. There is no slot with this name nor did you pass the value explicitly when calling the template. Return template without filling the template.
rasa_1_8564a5b6e7c6 | Traceback (most recent call last):
rasa_1_8564a5b6e7c6 |   File "/usr/local/lib/python3.6/site-packages/rasa/core/nlg/template.py", line 114, in _fill_template_text
rasa_1_8564a5b6e7c6 |     text = re.sub(r"{([^\n]+?)}", r"{0[\1]}", template["text"])
rasa_1_8564a5b6e7c6 | KeyError: 'text'