Please see guide on how to Cancel your Leave
Note: This depends still on your Company's setting. If you are not able to cancel you need to seek help from your HR Administrator to cancel the leave application.
If you Leave is still on pending status and you will cancel it, there is no need for approval. It will be cancelled directly. If the Leave was already approved, it will go back to the Approvers to Approve the Cancellation. This is to ensure that the Approving officer knows when the staff did not consume the applied leave.
In Express:
Step 1: Go to 
Step 2: Click on 
Step 3: Click on 
Step 4: Under Action column there should be this icon 
so you can cancel that leave.
In the Mobile Application:
Step 1: In the lower right click 
Step 2: Click on 
Step 3: Check on the Pending Status or at All Status and locate the Leave application you need to cancel and scroll down and click 