idn2 software package provides Internationalized domain names (IDNA2008) command line tool, you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install idn2
idn2 is installed in your system.
Make ensure the idn2 package were installed using the commands given below,
$ sudo dpkg-query -l | grep idn2 *
You will get with idn2 package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Development |
| Package | idn2 |
| Version | 0.10-3 |
| Description | Internationalized domain names (IDNA2008) command line tool |
| Sub Section | Devel |