Ivan Ustûžanin

<?php
$arr = [ 'id' => 1, 'name' => 'item1', 'items' => [
	[ 'id' => 2, 'name' => 'item2', 'items' => [], ],
	[ 'id' => 3, 'name' => 'item3', 'items' => [], ],
	[ 'id' => 4, 'name' => 'item4', 'items' => [
		[ 'id' => 5, 'name' => 'item5', 'items' => [], ],
		[ 'id' => 6, 'name' => 'item6', 'items' => [], ],
	], ],
], ];

function list_form_iterative(array $input) {
	$result = [ '<ul>', ];
	$state = [ [ 'array' => $input, 'keys' => array_keys($input), 'idx' => 0, ] ];
	for (; count($state) > 1 || $state[0]['idx'] < count($state[0]['keys']); $state[0]['idx'] += 1) {
		if (count($state) > 1 && $state[0]['idx'] === count($state[0]['keys'])) {
			array_shift($state);
			continue;
		}
		$key = $state[0]['keys'][$state[0]['idx']];
		$value = $state[0]['array'][$key];
		if (!is_array($value)) {
			$result[] = "<li>$key => $value</li>";
		}
		else {
			$result[] = "<li>$key => []</li>";
			if (!count($value)) continue;
			array_unshift($state, [ 'array' => $value, 'keys' => array_keys($value), 'idx' => -1, ]);
		}
	}
	$result[] = '</ul>';
	return implode("\n", $result);
}

echo list_form_iterative($arr);

<?php
$arr = [ 'id' => 1, 'name' => 'item1', 'items' => [
	[ 'id' => 2, 'name' => 'item2', 'items' => [], ],
	[ 'id' => 3, 'name' => 'item3', 'items' => [], ],
	[ 'id' => 4, 'name' => 'item4', 'items' => [
		[ 'id' => 5, 'name' => 'item5', 'items' => [], ],
		[ 'id' => 6, 'name' => 'item6', 'items' => [], ],
	], ],
], ];

function list_form_recursive(array $input) {
	static $level = 0;
	$self = __FUNCTION__;
	$result = [];
	if (!$level) {
		$result[] = '<ul>';
	}
	foreach ($input as $key => $value) {
		if (!is_array($value)) {
			$result[] = "<li>$key => $value</li>";
		}
		else {
			$result[] = "<li>$key => []</li>";
			if (!count($value)) continue;
			$level += 1;
			array_push($result, ...$self($value));
			$level -= 1;
		}
	}
	if (!$level) {
		$result[] = '</ul>';
		return implode("\n", $result);
	}
	else {
		return $result;
	}
}

echo list_form_recursive($arr);

<ul>
<li>id => 1</li>
<li>name => item1</li>
<li>items => []</li>
<li>0 => []</li>
<li>id => 2</li>
<li>name => item2</li>
<li>items => []</li>
<li>1 => []</li>
<li>id => 3</li>
<li>name => item3</li>
<li>items => []</li>
<li>2 => []</li>
<li>id => 4</li>
<li>name => item4</li>
<li>items => []</li>
<li>0 => []</li>
<li>id => 5</li>
<li>name => item5</li>
<li>items => []</li>
<li>1 => []</li>
<li>id => 6</li>
<li>name => item6</li>
<li>items => []</li>
</ul>

Мне нужно именно через функцию ImageGIF().

Caution When reading GIF files into memory, only the first frame is returned in the image object. The size of the image is not necessarily what is reported by getimagesize().

const photo = "https://blablabla.ru/sss.jpg?us=22&qq=11";
fetch(`https://example.site/example/example.php`, {
  method: 'POST',
  headers: {
    "Content-Type": "application/json",
  },
  body: JSON.stringify(photo),
});

$test = json_decode(file_get_contents('php://input'), true);
var_dump($test);

$text = preg_replace_callback('~<code[^>]*>.*?</'.'code>|#(\w+)~uim', fn($m) => $m[0][0] !== '#' ? $m[0] : "<a href=\"#{$m[1]}\">{$m[0]}</a>", $text);

Была бы просто опечатка, разобрался бы сам.