How to Start a message flow inside Inbox?

The main command you have to write in inbox is '/' for all the message flows to show up.

What is the use of quick replies?

To streamline the process of sending message flows by allowing users to quickly access and send message flows to contacts directly from the inbox

• You can filter the list of message flows by the last used or by name, and sorted alphabetically for ease of navigation.
• You can create a new message flow by clicking on the '+' icon, which then redirects you to the create message flow window.