Default Reply can be set in Settings -> Messenger -> Default Reply tab.
It is sent when your Messenger subscribed contacts type in something your bot cannot recognize, for example — they typed in something that doesn't match any of your Keywords.
NOTE: Default Reply can be triggered by emoji if contact type them in manually in Messenger. If the emoji is chosen from the list, it will not trigger the Default Reply due to Facebook API limitation.
It is a good call to provide some contact information so your contacts can reach out to admins instead of asking the questions your bot cannot answer. You can also use Buttons and Quick Replies to forward them in the right direction in case they get lost or even start a long Flow inside the Default Reply.
In case your Default Reply is enabled (you can turn it off with the toggle on the top) select one of two options: send it once in 24 hours or send it every time it is triggered by unknown inputs.
Please note that in order for the default reply to work, nothing needs to be done with the Starting step.
We also added an option to capture your contacts' inputs even before Default Reply goes off. You can use Last Text Input Custom Field that stores the very last input and can be sent to Admins as a notification or to external servers that will return dynamic content based on their input.
For example, your Default Reply can contain only one Action Step with Notify Admins Action that will immediately notify you about the question that was asked in a conversation.
Default Reply also features the button that can switch Default Reply's statistics. You can switch the statistics display from Current Trigger to Aggregated. The Aggregated display mode shows how many cotacts have gone through that flow overall, not limited to the number of people gone through the Default Reply itself.
TROUBLESHOOTING NOTES
Default reply is not triggered
If your Default Reply is not getting triggered, we have the following instructions for you:
1. Please check the firing settings, whether the Default Reply is set up to trigger "Once in 24 hours" or "Every time". If the option "Once in 24 hours" is chosen, then the Default Reply won’t be triggered every time.
2. Make sure that your Default Reply is Published and Enabled. If you see the small yellow dot like on the screenshot below - this means that your Default Reply is not Published. Click 'Edit Flow' button and then hit "Publish" button in the upper right corner of the page to save changes in the message, so it can get triggered and sent to contacts eventually.
Flow used for Default Reply has been deleted
If you see this in Automation -> Default Reply, this means that your Default Reply Flow was deleted.
If you deleted it by accident and you'd like to restore, please go to Flows -> Trash Folder. There you'll find your Default Reply Flow. Now you can either delete it permanently or restore:
If you restore it, it will not be attached back to your Default Reply automatically. The Flow will appear in the Flows tab. To attach it to Default Reply, please go to Settings -> Messenger -> Default Reply -> Set Another Flow -> choose the Default Reply Flow you've just restored. If you'd like to set up another Flow, you can go to Settings -> Messenger -> Default Reply -> Set Another Flow -> Create New Flow.
How to replace your Default Reply
If you need to replace your Default Reply Flow with another Flow, simply go to Settings -> Messenger -> Default Reply and click the "Replace" button here:
Then choose the Flow you need from the list of the Flows -> Select This Flow.
Hopefully this helps!