PWA, Polylang and subdomains

On the English version of your site, there is a web app manifest link to:

<link rel="manifest" href="https://en.cosmoyoste.com/wp-json/wp/v2/web-app-manifest">

On the Spanish version, there is this web app manifest link:

<link rel="manifest" href="https://es.cosmoyoste.com/wp-json/wp/v2/web-app-manifest">

Nevertheless, for both web app manifest:

https://en.cosmoyoste.com/wp-json/wp/v2/web-app-manifest
https://es.cosmoyoste.com/wp-json/wp/v2/web-app-manifest

The start_url is https://cosmoyoste.com/ and the lang for both is es. I would have expected the start_url to be language-specific and for the appropriate lang to be used in the English manifest.

The start_url and lang are being populated via home_url() and get_bloginfo('language') respectively: https://github.com/GoogleChromeLabs/pwa-wp/blob/ec984523a90d94afe49ebf65f0ec419b026322d4/wp-includes/class-wp-web-app-manifest.php#L131-L154

I am confused why Polylang isn’t returning the localized version of the home_url() even though the REST API request is being made to a localized hostname.

For the lang, I wonder if get_bloginfo( 'language' ) is incorrect and get_locale() should be used instead.

As a quick fix, try using this plugin code to filter the web app manifest:

add_filter( 'web_app_manifest', function( $data ) {
	if ( isset( $_SERVER['HTTP_HOST'] ) ) {
		$data['start_url'] = esc_url_raw( sprintf( 'https://%s/', wp_unslash( $_SERVER['HTTP_HOST'] ) ) );
	}
	$data['lang'] = str_replace( '_', '-', get_locale() );
	return $data;
} );

Many thanks @westonruter
I follow you on twitter since you gave a solution to use woocommerce with AMP.
It worked perfect; paste the code in my function child theme.
Sorry for replying late, I found the forum email in the spam tray.
Thanks!