chore: Raise error if environment variables are not set

app.py

@@ -85,11 +85,11 @@ def refusal_condition(query):
 with gr.Blocks() as demo:
     # Check if the API_URL and TOKEN are set
     if API_URL is None:
-        gr.Error("API_URL is not set as an environment variable.")
+        raise gr.Error("API_URL is not set as an environment variable.")
     if TOKEN is None:
-        gr.Error("TOKEN is not set as an environment variable.")
+        raise gr.Error("TOKEN is not set as an environment variable.")
     if MODEL_NAME is None:
-        gr.Error("MODEL_NAME is not set as an environment variable.")
+        raise gr.Error("MODEL_NAME is not set as an environment variable.")
 
     gr.Markdown(DESCRIPTION)