我已经安装了Composer并执行了以下命令：

composer require facebook/graph-sdk
composer require unsplash/unsplash
composer install

最后一个的输出是：

Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Nothing to install or update
Generating autoload files

但是，它不会生成供应商文件夹。我的目录中只有composer.json和composer.lock文件。我的composer.json文件看起来像这样：

{
    "require": {
        "unsplash/unsplash": "^2.5","facebook/graph-sdk": "^5.7"
    }
}