How to set the og:locale tag to bn_IN?

Hello,

Thanks for contacting us, and sorry for any inconvenience that might have been caused due to that.

Please follow the guide below to change the og:local value on your site:
https://rankmath.com/kb/open-graph-meta-tags/#og-locale

If the issue persists, please try applying the following filter on your site to change the value of og:locale property.

add_filter( "rank_math/opengraph/facebook/og_locale", function( $content ) {
        $content = 'bn_IN';
	return $content;
});

Here’s how you can add filters/hooks to your WordPress site:
https://rankmath.com/kb/wordpress-hooks-actions-filters/

Hope that helps, and please do not hesitate to let us know if you need our assistance with anything else.

Thank you.