Most users do not need a manual file download. The safest way to update is via OTA:
You only need a manual “Evpad Firmware Download” if the device won’t boot or OTA fails. Evpad Firmware Download
Before attempting a download, you must identify your exact hardware model. Installing the wrong firmware can "brick" the device (render it unusable). Most users do not need a manual file download
Some Evpad models have a hidden recovery partition with the stock firmware. You can access it by holding the reset button (inside the AV port) while powering on. You only need a manual “Evpad Firmware Download”
Websites to avoid: