Yes, you can allow employees to add nominees who can cover up the work during your absence. These nominees are notified when they are added and removed.
Please find the article and the video on Leave nominee feature which was available since the 6.3.1 version.
Article - https://help.orangehrm.com/hc/en-us/articles/360006397013-Apply-Leave
Video - https://help.orangehrm.com/hc/en-us/articles/360007725414-Leave-Nominee-Video-