A great way to give your chatbot visibility is to make your chatbot pop-up automatically when someone is on your Facebook Page. This works on desktop and mobile and is actually a Facebook Option within your account.
Here are the steps to make that possible :
1 - Go to your Facebook Page settings
2 - Go to the Messaging Tab
3 - Check the "Prompt visitors to send messages"
This option can take a few days to get active as you need to be "online” or your Page needs to be “very responsive to messages."
This means your bot you will have the very responsive to messages badge but it can take some time, so remember to be patient.