Update chain_app.py

chain_app.py

@@ -444,7 +444,7 @@ async def on_chat_start():
         await cl.Message(
             content="Im The small Llama!. one of the best open source models released by Meta! i am the small version of meta's open source LLMs. i was configured by Artin Daneshvar and Sadra Noadoust, 2 iranian students to help you, how can i assist you today ? "
         ).send()
-    if chat_profile == 'gemma-9B':
+    if chat_profile == 'gemma2-9B':
         await cl.ChatSettings(
             [
                 Select(