rasa: Can not connect chatbot to fb

Rasa Core version: 0.10.4

Python version: python3

Operating system (windows, osx, …): Ubuntu

Issue: I can not connect my chatbot to fb messenger platform. I am using this command : python3 -m rasa_core.run -d models/dialogue -u projects/default/model_20180810-113049 --port 5002 --connector facebook --credentials fb_credentials.yml

My fb_credentials.yml file: verify: “minh-bot” secret: $MY_SECRET page-access-token: $MY_PAGE_ACCESS_TOKEN

I am using ngrok for local testing. when I set up webhook, ngrok gave me : GET /webhook 200 OK . but when I send messages from fb messenger, chat bot doesn’t reply

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