With "Keyword", your users can easily jump to sub flows by typing in keywords rather than being lost in menus or buttons.
go "Automation" from the sidebar
click "Keywords"
for "default reply", see explaination below
click "+ New Keyword"
choose a condition from "is", "contains" or "starts with"
put one or more than one keyword, separated by only commas, no space allowed
choose a sub flow to send
"Default Reply" is sent when the bot doesn't know what to reply. When the active button is off or no sub flow was chosen for "Default Reply", the main flow will be sent.
TIP - So when you build and test flows, you can reply anything to quickly re-start the conversation.
You can also adjust the frequency to send "Default Reply". Its default value is set to fire "Every Time".
Want to have a smarter bot?
Want to reply a sentence rather than a sub flow?
Want your bot to understand more human languages rather than just keywords?
Try Google Dialogflow Integration! Check how to setup Dialogflow.