Update app.py

app.py

@@ -85,5 +85,5 @@ async def run_code(code: Code):
 
 @app.get("/chart/{project_id}/{chain_id}/{session_id}")
 async def get_chart(project_id: str, chain_id: str, session_id: str):
-    pdf_path = f"graph_{project_id}_{chain_id}_{session_id}.pdf"
+    pdf_path = f"graphs_{project_id}_{chain_id}_{session_id}.pdf"
     return FileResponse(pdf_path, media_type="application/pdf")