404. That’s an error.
The requested URL /add?source=atgs&feedurl=https://rongbay.com/rss/Vinh-Phuc/c2_Dien-thoai-may-tinh-bang.rss was not found on this server. That’s all we know.
/add?source=atgs&feedurl=https://rongbay.com/rss/Vinh-Phuc/c2_Dien-thoai-may-tinh-bang.rss