In your project, click on the TASK BOARD tab.

When you select a task list, all tasks in this task list will be selected and all tasks can be modified, using the Tasks selected toolbar at the bottom of the page:


Furthermore, individual tasks can also be multi-selected:

The following modifications can be made to the task lists of tasks:
Edit
This option allows you to Mass edit tasks:

Field | Description |
Start date | Select the start date of all tasks. |
Duration (days) | Select the duration of the tasks. |
Due date | This is automatically filled when the duration is entered. |
Assign to project members | Assign the tasks to members. |
Priority | Select the priority of that tasks. |
Status | Select the status of all tasks. |
Move to
This option allows to move the task(s) to another task list:

Copy to
This option allows to copy a task or multi-selected tasks:

Delete
This option allows you to delete a task or multi-selected tasks:

Click Proceed.
Clear selection
This option allows to clear a selection of tasks.