Install bitlbee-plugin-otr by entering the following commands in the terminal:
sudo apt update sudo apt install bitlbee-plugin-otr
Description:
IRC to other chat networks gateway (OTR plugin)
This program can be used as an IRC server which forwards everything you say to people on other chat networks: Jabber (which includes Google Talk), ICQ, AIM, MSN and Twitter. . This package contains a plugin that adds support for Off-The-Record encryption of instant messages.
Homepage: http://www.bitlbee.org/
Version: 3.5.1-1build1
Section: universe/net