removing cookies

hi, I’m using InsertPHP for a privacy policy page where there is a for deleting cookies

[insert_php]
$test_cookie = $_POST["test_cookie"];
	$settings = $_POST["settings"];
	$word = $_POST["word"];
	$volume = $_POST["volume"];
	$silence = $_POST["silence"];
	$www = $_POST["www"];
	$slim = $_POST["slim"];
	$qtrans = $_POST["qtrans"];

	$next_month = time() + (30 * 24 * 60 * 60); 

	if (isset($test_cookie) ) {

		setcookie("wordpress_test_cookie", "", time()-3600, "/", "mywebsite.com", 1);
		setcookie("no_test_cookie", "", time()+$next_month, "/", "mywebsite.com", 1);

	}

	if (isset($settings) ) {

		foreach($_COOKIE as $key => $value) {
			if(substr($key, 0, 12) == 'wp-settings-') {
				setcookie($_COOKIE[$key], "", time()-3600, "/", "mywebsite.com", 1);
			}
		}

	setcookie("no_settings", "", time()+$next_month, "/", "mywebsite.com", 1);

	}

	if (isset($word) ) {

		foreach($_COOKIE as $key => $value) {
			if(substr($key, 0, 10) == 'wordpress_') {
				setcookie($_COOKIE[$key], "", time()-3600, "/", "mywebsite.com", 1);
			}
		}

	setcookie("no_word", "", time()+$next_month, "/", "mywebsite.com", 1);

	}	

	if (isset($volume) ) {

		setcookie("jwplayer_volume", "", time()-3600, "/", "mywebsite.com", 1);
		setcookie("no_volume", "", time()+$next_month, "/", "mywebsite.com", 1);

	}

	if (isset($silence) ) {

		setcookie("jwplayer_mute", "", time()-3600, "/", "mywebsite.com", 1);
		setcookie("no_silence", "", time()+$next_month, "/", "mywebsite.com", 1);

	}	

	if (isset($www) ) {

		setcookie("newsletter", "", time()-3600, "/", "mywebsite.com", 1);
		setcookie("no_www", "", time()+$next_month, "/", "mywebsite.com", 1);

	}		

	if (isset($slim) ) {

		setcookie("slimstat_tracking_code", "", time()-3600, "/", "mywebsite.com", 1);
		setcookie("no_slim", "", time()+$next_month, "/", "mywebsite.com", 1);

	}

	if (isset($qtrans) ) {

		setcookie("qtrans_cookie_test", "", time()-3600, "/", "mywebsite.com", 1);
		setcookie("no_qtrans", "", time()+$next_month, "/", "mywebsite.com", 1);

	}
[/insert_php]

I don’t know why but it doesn’t works, where I’m doing wrong?

https://ww.wp.xz.cn/plugins/insert-php/