I need to save a UTF-8 text in a file with PHP using this code:

<?php

$filename = "";
if ($handle = opendir("test")) {
    while (false !== ($file = readdir($handle))) {
        
        $filename = $file;
    }
    closedir($handle);
}

$arr = array(
    "name" => "اصغر",
    "family"=> "فرهادی",
    "Movies" => [
        "City" => "[جدایی نادر از سیمین]",
        "detail" => [
            "yearOf" => "2011",
            "language" => "persian"
        ]
    ]
);


$json =  json_encode($arr);
$encoding = mb_detect_encoding($json);
echo $encoding."n";

$json1 = mb_convert_encoding($json, "UTF-8");

$encoding2 = mb_detect_encoding($json1);

echo $encoding2."n";

$h = fopen("out.txt","a+");
fwrite($h, $json1."n");
fclose($h);

I run this code in the console using this command:

php index.php

and output is:

ASCII ASCII

and the content of the output file is:

{“name”:”u0627u0635u063au0631″,”family”:”u0641u0631u0647u0627u062fu06cc”,”Movies”:{“City”:”[u062cu062fu0627u06ccu06cc u0646u0627u062fu0631 u0627u0632 u0633u06ccu0645u06ccu0646]”,”detail”:{“yearOf”:”2011″,”language”:”persian”}}}

but I need to save the result in the file in Persian transcript. I also checked the iconv function, but the result was the same.