does not work

src/index.js

@@ -1,6 +1,8 @@
 // Put all packages together.
 // Used to generate umd/index.prod.js
 
+console.log("hello!");
+
 import React from 'react';
 import { createRoot } from 'react-dom/client';
 
@@ -10,6 +12,21 @@ import allMessages from './messages.json';
 import TinodeWeb from './views/tinode-web.jsx';
 import HashNavigation from './lib/navigation.js';
 
+/*
+// Load just one language.
+const messageLoader = {
+  'de': _ => import('./i18n.min/de.json'),
+  'en': _ => import('./i18n.min/en.json'),
+  'es': _ => import('./i18n.min/es.json'),
+  'fr': _ => import('./i18n.min/fr.json'),
+  'ko': _ => import('./i18n.min/ko.json'),
+  'ro': _ => import('./i18n.min/ro.json'),
+  'ru': _ => import('./i18n.min/ru.json'),
+  'zh': _ => import('./i18n.min/zh.json'),
+  'zh-TW': _ => import('./i18n.min/zh-TW.json')
+};
+*/
+
 // Detect human language to use in the UI:
 //  Check parameters from URL hash #?hl=ru, then browser, then use 'en' as a fallback.
 const { params } = HashNavigation.parseUrlHash(window.location.hash);
@@ -19,16 +36,21 @@ const language = (params && params.hl) ||
   navigator.userLanguage ||
   'en';
 
+// Make sure names like 'en_GB' and 'en-GB' consistently use '-'.
+const normalized = language.replace('_', '-');
 // Get the base language 'en' from a more specific 'en_GB' or 'en-US' as a partial fallback.
-const baseLanguage = language.toLowerCase().split(/[-_]/)[0];
+const baseLanguage = normalized.split(/[-]/)[0].toLowerCase();
 
 // Try the full locale first, then the locale without the region code, fallback to 'en'.
-const htmlLang = allMessages[language] ? language : allMessages[baseLanguage] ? baseLanguage : 'en';
+// const htmlLang = messageLoader[normalized] ? language : messageLoader[baseLanguage] ? baseLanguage : 'en';
+// const messages = await messageLoader[htmlLang]();
+const htmlLang = allMessages[normalized] ? language : allMessages[baseLanguage] ? baseLanguage : 'en';
 const messages = allMessages[htmlLang];
 
+console.log("language:", htmlLang, "messages loaded", messages);
+
 // Set lang attribute of the HTML element: <html lang="XX">
 document.getElementsByTagName('html')[0].setAttribute('lang', htmlLang);
-
 // Render the app.
 const root = createRoot(document.getElementById('mountPoint'));
 root.render(