SHELL

laravel upgrade php version

// Go to your composer.json file in your project root
// Then search for the below configuration. And change 
// it to whatever version you need
Like this :
"php": "7.0.7"
or something like this :
"php": "^7.3|^8.0",

//Then run composer install
composer install

laravel 7 upgrade

$>which composer
/usr/local/bin/composer

$>php -d memory_limit=512M /usr/local/bin/composer update
...