Um, not seeing where this setting is. Usually I just long tap the notification when I get one.. Then it redirects me to the settings of the app to change it.  

Zoho app > Hamburger menu > Gear Icon settings > Manage Notifications

All I see is "Allow sound and vibration"  and  "Deliver quietly". 

I'm not seeing the option for "Sound only"

I'm on Samsung note 10+

Thank you