PHP arabic character encoding issue

Question

I am getting one arabic site meta keywords using get_meta_tags. It gives keywords like

ÇÖÝ ãæÞÚß ,ÇÚáÇã Ïæá ÇáÚÇáã ,ÇäÇÔíÏ ÇÓáÇãíÉ ,ÇáÈË ÇáãÈÇÔÑ ,ÊÍæíá ÇáÚãáÇÊ,ÊáÝÒíæä ãÈÇÔÑ ,ÌÇÝÇ ÓßÑÈÊ,ÍÇáÉ ÇáØÞÓ

Now I want to convert this into arabic letters and need to pass it as API parameter .

How to convert this letters into arabic characters?

If I want to display it into browser means I have solutions using below functions or header.

1. mb_convert_encode($keywords,'HTML-ENTITIES','UTF-8');
2. <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

But I need to pass these keywords as arabic into an API parameter. So need to convert this into arabic characters, please help me.