upload.php

<?php

    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, 'https://api.imgur.com/3/image');
    curl_setopt($curl, CURLOPT_TIMEOUT, 30);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array('Authorization: Client-ID ' . 'app_id'));
    curl_setopt($curl, CURLOPT_POST, 1);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($curl, CURLOPT_POSTFIELDS, base64_encode(file_get_contents($request->file('image')->path())));
    $response = curl_exec($curl);
    curl_close($curl);

    return response()->json(json_decode(($response)));