Register as a developer, you can register at the following website. https://developers.facebook.com/async/registration+
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Click Messager>Settings>Access Tokens, click 'Generate token'. And copy the tokenand paste it on the other filewebhook setting.
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Click Messager>Settings>Webhooks, Click 'Add Callback URL'.
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Enter Callback URL and token. URL is https://Domain:9001/fb/webhook, Domain is your Web Domain.The Token is cloudfon-facebookgenerated on the previous step.
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Click Messenger>Settings, click 'Add subscriptions'
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