If you wish to turn off your bot's Welcome message, navigate to Facebook Messenger → Flows and toggle to off the button next to the Welcome message:
Why would I want to turn off the Welcome message?
The Welcome message is very helpful for new customers but there are a couple cases where it might interfere with other things you're doing. We recommend turning off the Welcome message if:
1) You are using another bot as your primary bot on the Facebook page and adding Octane AI as a secondary bot.
2) You have a customer service team who replies to all Facebook messages manually.