NLP
Although natural language understanding chatbots are quite complex, this block is very simple. It’s just sending messages that your chatbot gets from end-users to the NLP engine like Dialogflow.

Sending user messages to an external NLP engine
Usually, this block is used in the “default” skill so that every message that the user is sending to your chatbot is processed by the NLP engine automatically.
“New session” set to true will start a new NLP session. Otherwise, all messages sent from the same chatbot users will be included in the same NLP session.
You can add contexts so that only those intents that are expecting these input contexts will be triggered.