Install asterisk-doc by entering the following commands in the terminal:
sudo apt update sudo apt install asterisk-doc
Description:
Source code documentation for Asterisk
Asterisk is an Open Source PBX and telephony toolkit. . This package contains the documentation for configuring an Asterisk system.
Homepage: http://www.asterisk.org/
Version: 1:13.18.3~dfsg-1ubuntu4
Section: universe/doc