What to do in case your Time-off request is rejected depends on whether you want to re-submit it or cancel/delete it.
If you have requested time off and your request is rejected by your manager or HR for any reason, you will receive a notification via email along with a reason why the application was rejected. You can then resubmit your time-off request through the time-off document, including your reasoning. The approver will receive a notification and an email to either approve or reject the request.