Fixed it…well solved my problem anyway.
I was thinking that all I am trying to do is play an alarm sound on an echo at a given time.
So started looking into just playing mp3 files from HA on an echo and sure enough you can!
So you just need to find an alarm tone mp3 file on the internet of your choice and then upload to HA and play from your automation. This YoutTube video helped (4) ALEXA CUSTOM MP3’s (Using Home Assistant) - YouTube