How to install php phantomjs

{
        "scripts": {
            "post-install-cmd": [
                "PhantomInstaller\\Installer::installPhantomJS"
            ],
            "post-update-cmd": [
                "PhantomInstaller\\Installer::installPhantomJS"
            ]
        },
        "config": {
            "bin-dir": "bin"
        },
        "require": {
                "jonnyw/php-phantomjs": "4.*"
        }
}

<?php
    require "vendor\autoload.php";
    use JonnyW\PhantomJs\Client;
    // require_once &#39;vendor_phantomjs/jonnyw/php-phantomjs/src/JonnyW/PhantomJs/Client.php&#39;;
    $client = Client::getInstance();
    $client->getEngine()->setPath(&#39;E:/xampp/php/phantomjs.exe&#39;);
    //上面一行要填写自己的phantomjs路径
    /** 
     * @see JonnyW\PhantomJs\Http\PdfRequest
     **/
    $delay = 7;
    $request = $client->getMessageFactory()->createPdfRequest(&#39;https://www.baidu.com/&#39;, &#39;GET&#39;, 5000); //参数里面的数字5000是网页加载的超时时间，放在网络问题一直加载，可以不填写，默认5s。
    $request->setOutputFile(&#39;E:/document.pdf&#39;);
    $request->setFormat(&#39;A4&#39;);
    $request->setOrientation(&#39;landscape&#39;);
    $request->setMargin(&#39;1cm&#39;);
    $request->setDelay($delay);//设置delay是因为有一些特效会在页面加载完成后加载，没有等待就会漏掉
    /** 
     * @see JonnyW\PhantomJs\Http\Response 
     **/
    $response = $client->getMessageFactory()->createResponse();
    // Send the request
    $client->send($request, $response);