Auto voice reply to phone calls?

I'm looking for a way to automatically answer any incoming phone calls with a voice message, i.e. an autoresponder. So actually much like voicemail, except I don't want people to leave me messages. I just want to play a welcome message or "I'm currently not available by phone" and refer them to my email address or Whatsapp. Upon looking around I find tons of solutions which can auto respond by SMS, i.e. sending an auto reply text message. But that's not what I'm looking for, I prefer to play back a voice message. Is there a way to do this, either natively from within Android or with an app?