Update app.py

app.py

@@ -92,7 +92,7 @@ async def run_code(code: Code, request: Request):
     # return FileResponse(file_path, media_type="application/pdf", filename="graph.pdf")
     return {
         "message": "Graph created succesfully!",
-        "url": request.url + f"/chart/{code.project_id}/{code.chain_id}/{code.session_id}"
+        "url": str(request.url) + f"/chart/{code.project_id}/{code.chain_id}/{code.session_id}"
     }