Install asterisk-mp3 by entering the following commands in the terminal:
sudo apt update sudo apt install asterisk-mp3
MP3 playback support for the Asterisk PBX
Asterisk is an Open Source PBX and telephony toolkit. . This package provides support for playing MP3-encoded files in Asterisk. . For more information about the Asterisk PBX, have a look at the Asterisk package.