Message composer is the place where users can type their replies. Nonetheless, you may also opt to disable this feature to force users to only interact using a Button or a Quick Reply.
Go to menu >> bot persistent menu >> edit >> untick “allow keyboard input”
Or, you can follow the steps below to know how to Enable/Disable the message composer inside a flow.
Step 1: Select any flow which you need to add this feature.
Step 2: Click the Action button on the flow builder and choose “Enable Message Composer” or “Disable Message Composer”.