Unique ringtone for Voicemail alerts

Would really appreciate custom ringtones for Voicemail alerts. I use RingCentral partly as a pager where people leave their number for me to call back, but with the gentle default alert, it's not necessarily catching my attention (especially at night). Would like to set a more catching signal that might also play for longer than a single beep.

I prefer not to just "answer phone calls" when on call as I'm often in the middle of something and letting it go to voicemail unecessarily delays the caller from just leaving their number for me.