First you need to have “php” installed,
Once it’s done, go to https://getcomposer.org
Go to download section and copy-paste the scrip into your terminal
You will now have a file “composer.phar” into your directory.
Finally, move it to / usr / local / bin to be able to access it globally on the system.
To check : type “composer -v” into your terminal. If you have a version it’s good.
Feel free to like this video if you succeed, thanks 😉