We know that utf8_encode is deprecated since PHP 8.2.0 and will be removed in PHP 9 https://php.watch/versions/8.2/utf8_encode-utf8_decode-deprecated

So the alternative can be:

$oldSample = ["\x5A\x6F\xEB"];
$result= array_map
(
    function ($item){
        return mb_convert_encoding($item, "UTF-8", mb_detect_encoding($item));
    }, 
    $oldSample
);
var_dump($result);

Documentation:

• https://www.php.net/manual/en/function.mb-convert-encoding.php
• https://www.php.net/manual/en/function.mb-detect-encoding.php

try

$string = mb_convert_encoding($string,'HTML-ENTITIES','utf-8');

The encoding appears to be Windows-1251. Encode to UFT-8 using:

$html_utf8 = mb_convert_encoding($html, "utf-8", "windows-1251");

Decode back to Windows-1251 using:

$html_1251 = mb_convert_encoding($html, "windows-1251", "utf-8");