download image from url, save to '/dalle_images/' and return a full url of the image

function download_image($url){
    $extension = pathinfo($url, PATHINFO_EXTENSION);
    $filename = uniqid() . "." . $extension;
    $destinationFileName = __DIR__ . '/dalle_images/' . $filename;
    file_put_contents($destinationFileName, file_get_contents($url));
    return '/dalle_images/' . $filename;
}

download_image(http://url.com/image.png)