Interface HTML by PHP to show info from endpoint JSON API

index.php

<?php

require('Requirements.php');

$req = new \GilbertoTavares\Requirements();
$req->apiCall();
$req->convertJson();
$req->outputData();

Requirements.php

<?php
declare(strict_types=1);
/**
 * Interface to JSON endpoint.
 */

namespace GilbertoTavares;

/**
 * Class to GET JSON and print.
 */
class Requirements
{

    /** Endpoint URL */
    const URL = 'https://api.wp-healthcheck.com/v1/requirements';

    /** Store JSON object **/
    private $json;

    /** Parameters **/
    private $params;

    /**
     * Get content json of endpoint
     *
     * @return null
     **/
    public function apiCall()
    {
        if ($this->httpCode() === 200) {
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_URL, self::URL);
            $this->json = curl_exec($ch);
            curl_close($ch);
        }
    }

    private function httpCode()
    {
        $ch = curl_init(self::URL);
        curl_setopt($ch, CURLOPT_HEADER, true);
        curl_setopt($ch, CURLOPT_NOBODY, true);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_TIMEOUT, 10);
        $output = curl_exec($ch);
        $httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);
        return $httpcode;
    }

    public function convertJson()
    {
        if (!empty($this->json))
        {
            $this->params = json_decode($this->json);
        }
    }

    public function outputData()
    {
        if (empty($this->params))
        {
            echo 'Endpoint unavailable';
            return;
        }
        $minrec = ' (minimum: %s, recommended: %s)';
        $output = "MySQL$minrec\nPHP$minrec\n";
        printf(
            $output,
            $this->params->mysql->minimum,
            $this->params->mysql->recommended,
            $this->params->php->minimum,
            $this->params->php->recommended
        );
    }
}