How do I upload an extended absence greeting on voicedge

Hello @user_0bb5bb, and thanks for reaching out on our Comcast Business Support Community forums.  

To make sure we're providing the right guidance, are you looking to use the extended absence greeting for an individual user's voicemail box/extension, or an Auto Attendant (the main business greeting/menu that answers incoming calls)?

By answering this question we'll have a better idea of how we can assist you.