change response on the start message

backend/app.py

@@ -1,6 +1,6 @@
 import logging
 from telegram import InlineKeyboardButton, InlineKeyboardMarkup, Update, WebAppInfo
-from telegram.ext import ApplicationBuilder, ContextTypes, CommandHandler, CallbackQueryHandler
+from telegram.ext import ApplicationBuilder, ContextTypes, CommandHandler
 import os
 from dotenv import load_dotenv
 
@@ -13,25 +13,33 @@
 load_dotenv()
 
 TOKEN = os.getenv('TELEGRAM_TOKEN')
+WEB_APP_URL = os.getenv('WEB_APP_URL')
 
 
 async def start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
-    """Sends a message with three inline buttons attached."""
+    """Sends a photo with an inline button attached from local directory."""
 
     keyboard = [[
-        InlineKeyboardButton("Let's GO!", web_app=WebAppInfo(url="https://ghost-solder.github.io/TLingua/"))
+        InlineKeyboardButton("Let's GO!", web_app=WebAppInfo(url=WEB_APP_URL))
     ]]
-
     reply_markup = InlineKeyboardMarkup(keyboard)
 
-    await update.message.reply_text("Let's GO!", reply_markup=reply_markup)
+    photo_path = 'images/start-message.png'
+
+    with open(photo_path, 'rb') as photo_file:
+        await context.bot.send_photo(
+            chat_id=update.effective_chat.id,
+            photo=photo_file,
+            caption='Welcome to TLingua! 🎉🎉🎉\n\nAre you ready for a completely new language experience? 🥳',
+            reply_markup=reply_markup,
+        )
 
 
 if __name__ == '__main__':
     application = ApplicationBuilder().token(TOKEN).build()
 
-    application.add_handler(CommandHandler("start", start))
+    start_handler = CommandHandler('start', start)
+    application.add_handler(start_handler)
 
     # Run the bot until the user presses Ctrl-C
     application.run_polling(allowed_updates=Update.ALL_TYPES)
-