Quick reply can be enabled in your Profile
It is a member selectable option that is usually left to member preference.
Profile > Look and Layout Preferences > Use quick reply on topic display
If it is your preference to set all Members options for Quick Reply for them:
Admin > Layout Settings > Member Options
Click: Configure guest and new user options for this theme
Look For: "Use quick reply on topic display"
Choose one of the following:
Show on by default: Quick Reply is always open
Show off by default: Quick Reply is always closed
- Click the expand button to open it.
Click: Save
Click: Remove all members options and use the defaults
Click: Ok