Converting Unsupported Audio files to 3CX WAV Format
3CX allows you to import audio files only in below WAV format to be used as the system prompts:
Format: WAV
Channel: Mono
Bit rate: 8 kHz
Sampling: 16 bit
To convert an audio file (for example an *.mp3 file your professional recording company has created for you) you can use this Online Audio Converter Tool at below link:
https://www.3cx.com/docs/converting-wav-file/