How to set Voice Prompt
To add or change Voicemail Prompt for an extension:
Login 3CX extension, at left side tab menu, “….”, > “settings” > “Greetings”
Click “Upload” button to upload windows “wav” file for each status.
If you have mp3 or other format of audio files, or the wav file with different audio encoding format, visit this site to convert it to wave file
By clicking “Record Greeting”, there will be a pop up dialog. Input the file name and you will receive a call. Follow the instructions to record your voice prompt.