If eMMC is wiped this image will boot from SD/USB: https://chewitt.libreelec.tv/testing/LibreE…etek-hub.img.gz and once LE is running and you have SSH access you can download the same image to /storage and write it to eMMC using emmctool.
If eMMC is not wiped and vendor u-boot is still trying to do some form of recovery the following are the factory update/restore images that can be loaded from SD/USB to recover the Android OS. These are not Amlogic burning tool images (which I don't have).
If eMMC is not wiped but vendor u-boot cannot recover things (is broken some way) the worst case scenario is to open up the box (screws are behind the foot pads) and short pins on the emmc chip to disable it. This prevents vendor u-boot (or whatever remains of it) from interfering in boot and effectively forces SD or USB boot; so you can use the AMLGX image I linked above. It works but most users feel uncomfortable about sticking screwdrivers on memory chips to short pins and it's best done with UART access so you can see what's happening.
In all cases, having the UART cable that WeTek shipped in the box connected so you can see what's actually happening and/or where things are failing is always a good move.