SHELL

upgrade composer version

composer self-update

composer update

php composer.phar update

composer update phar comand

sudo -u nginx php composer.phar update

composer_update

composer update

composer require doctrine/dbal

update composer php version

php7.3 -f /usr/local/bin/composer update

composer update

composer self-update

upgrade composer

 To update composer command just find location of composer.phar and update as:
 where composer 	#Retrieves you location of your composer.phar
 cd path_to_composer.phar #Move to directory with composer.phar
 php composer.phar self-update	#Update your composer