The firmware for an Allwinner A23 device is not a single file but a complex stack of several layers: Bootloader (Boot0/U-Boot):
: A classic alternative to PhoenixSuit, often used for older tablets when a single .img file is provided. allwinner a23 firmware
Never download firmware from obscure ".tk" or ".ml" domains offering "A23_Universal_FINAL.zip." Universal firmware does not exist. You will brick your tablet. The firmware for an Allwinner A23 device is