To cancel an Approval request click on the relevant link in the relevant approval email, or into the My Approvals area of your platform.
Use the Workflow Filters to locate the approval request you wish to cancel.
Under the Actions menu to the right of this approval item, click Cancel
You will have to select Yes in the pop-up confirmation prompt that will appear:
This will trigger a cancellation email confirmation, and the approval item will then show as Cancelled in your Workflow Area and filters.