Once you have installed composer add the composer bin folder to your path to execute commands such as laravel new project
and valet park
The command append it to your existing path on a Linux Mint / Ubuntu or equivalent system is:
echo 'export PATH="$PATH:$HOME/.config/composer/vendor/bin"' >> ~/.bashrc
Note:
Do not sudo composer require. If you do that Composer will be install at ~./composer
instead of the correct location of ~/.config
References: