404. That’s an error.
The requested URL /add?source=atgs&feedurl=https://rongbay.com/rss/Yen-Bai/c20_Xe-may-Xe-dap.rss was not found on this server. That’s all we know.
/add?source=atgs&feedurl=https://rongbay.com/rss/Yen-Bai/c20_Xe-may-Xe-dap.rss