If you would like to edit a task title there are several ways to do it.
Option 1. Click on the edit button
Hover over a task, next to the task title
A icon, will be shown to edit on task title
Click on the icon
Change to desired name
Hit ENTER to save the changes
Option 2. Rightclick on the task and edit
The second way to edit a task title is
Rightclick on task column or kanban card
Change to desired name
Hit ENTER to save the changes