There are multiple places where you can assign tasks in ClickUp. 

To assign a task, click the people icon in any location.

You can assign to one person, multiple people, a Team, or Multiple Assignees.

Assign Tasks

You can assign tasks in the following ways:

• When Creating a task.
• From List view.
• From Board view.
• From Calendar view.
• Using the Bulk action toolbar.
• Using /Slash Commands.