On the Header click on User Name, It will redirect you to UserProfile.
In User Profile Page you can see Three grids namely Details grid, Edit Details grid, and the Last grid contains three tabs namely Leave Request, Open Works, Pay Slip.
From Leave Request Tab you can apply leave by clicking on "New Request Leave" button.
Click on "New Request Leave" button you will get a page where it contains fields like Leave type dropdown, Start and End date and Description box.
After filling all the details if you want to save it as draft click on "Save as Draft" and if you want to send your leave request click on "Send Leave Request" button.
In this you can apply Leave request from User profile.