Outgoing webhooks allows you to subscribe to certain events in the conversation. This is useful if you would like to add triggers on your side based on things happening in the conversation. It's also useful if you would like to keep track of conversations in real time.
Head to the webhook page in the integration section on the left sided menu and click on add and then click on outgoing as a type. Once you have done so you have to select the topics that you would like to subscribe to.