Chatbot with TensorFlow

What’s a better way to create a chatbot in TensorFlow?

Cent 7
TensorFlow 1.5
Installation is complete

I’m going to create a conversation bot
The plan will be integrated with the “Botpress” I have already created

I was able to search Dialogflow, but is there a charge?

① Create a bot with TensorFlow
② Connect TensorFlow Bot and Botpress