How can I change the chapter numbers in Bengali numerals/words [duplicate]

How can I change the chapter numbers in Bengali numerals/words. The chapter numbers are coming in Arabic format by default, instead of specifying numeral in font option.

\documentclass[12pt]{book}
\usepackage{fontspec}
\usepackage{polyglossia}
\setmainlanguage[numerals = Bengali, changecounternumbering=true]    {bengali}

\begin{document}

\chapter{ভূমিকা}

\end{document}


The above code give the following result

I expect an output like this

অধ্যায় ১

অধ্যায় ২ ...

or like this

প্রথম অধ্যায় (=First Chapter)

দ্বিতীয় অধ্যায় (=Second Chapter)

• Welcome to TeX.SX! See here Jun 28 '17 at 18:06
• Try package latexbangla on CTAN. The polyglossia package's support for Bengali is still poor/incomplete, and I remember a previous question on this site asking about how to contribute improvements and the maintainer of polyglossia wasn't responsive. Jun 28 '17 at 18:52
• Thanks @TeXnician, the following line solved the problem \renewcommand\thechapter{\bengalinumeral{chapter}}. However, It would be more "natural" if I get the output like "প্রথম অধ্যায়"
– Amit
Jun 28 '17 at 19:12