Make sure your Ubuntu is up to date and patched.
$ sudo apt update $ sudo apt upgrade
Composer is available within Ubuntu’s default software repositories, making it possible to install it using conventional package management tools. After confirming the installation,
apt will install Composer and all required dependencies.
$ sudo apt install composer -y
Check composer version
$ composer -V # OUTPUT Composer 1.10.1 2020-03-13 20:34:27