Add Task from Gantt

You can add tasks from Gantt. 

1. Go to your project. By default you are taken to the Interactive Gantt. If not, click on the Interactive Gantt from the views.
2. From the Gantt menu bar, Click on the Plus icon and then click on Task. 
3. This will add a row in your project plan. 
4. Enter your task details and click Save.

You can also add sub-tasks, Milestones, Predecessor, Successor, etc from here.

To Add Multiple Tasks.
At times when creating your WBS, it is more convenient to add multiple tasks in one shot, and then go back to schedule them. To achieve this

1. Go to the Interactive Gantt view of the project.
2. Click on the plus icon, then select Multiple. 
3. This opens a popup where you can enter task name; one on each line.
4. Upon Submit, multiple tasks are created 

To read about Gantt features, please click here.