Currently, our Opsgenie platform does not support Serbia for voice notification. This has impacted teams of engineers in Serbia who need to be on-call. The inability to add their Serbian phone numbers for voice notification is causing significant communication issues and hindering their ability to respond to emergencies promptly. 

We would like Opsgenie to add support for Serbia phone numbers in their voice notification system. 

We hope this request is considered and implemented at your earliest convenience.