You cannot flash this via the normal "Update & Backup" app. You need a PC, a USB male-to-male cable, and a tool called Rockchip Batch Tool or AndroidTool (RKDevTool).

Disclaimer: As an AI, I cannot host files directly. The links below point to reputable communities (FreakTab, 4PDA, GitHub) that have been vetted over years. Always scan downloaded files with antivirus software.

If you proceed to update firmware:

This is the most stable version for the EP-68. It supports older Wi-Fi chips and is less likely to crash.