The is an entry-level device; its firmware update mechanism may be less robust than brands like Asus or TP-Link. If your device is working fine and no security issues have been published, you do not need to update just for the sake of updating .
If this page does not load, your unit lacks a web-based recovery system. You would then need a serial TTL console (advanced users only). Update Software in WISE TIGER WT-RT8501