blank image issue on multiple req

controller.py

@@ -605,6 +605,10 @@ def groq_chart(csv_url: str, question: str):
                 except Exception as e:
                     print(f"Error deleting cache DB file: {e}")
                     
+            chart_dir = "generated_charts"
+            if not os.path.exists(chart_dir):
+               os.makedirs(chart_dir)
+                    
             data = clean_data(csv_url)
             with current_groq_chart_lock:
                 current_api_key = groq_api_keys[current_groq_chart_key_index]