Install asterisk-core-sounds-fr by entering the following commands in the terminal:
sudo apt update sudo apt install asterisk-core-sounds-fr
asterisk PBX sound files - Canadian French
Asterisk is an Open Source PBX and telephony toolkit. It is, in a sense, middleware between Internet and telephony channels on the bottom, and Internet and telephony applications at the top. . Asterisk includes a set of standard sound files in various formats. The core part of that collection in Canadian French, by voice actress June Wallack, is contained in various encodings in packages asterisk-core-sounds-fr-*; this package registers these through the alternatives system to provide the default "fr" (French) and "fr_CA" (Canadian French) sounds.