Based on the screenshot, you have an alternative bootloader installed (OpenWrt U-Boot)?
If yes, select option 6 and install the OpenWrt itb recovery firmware (the "ubootmod" version!! : openwrt-mediatek-filogic-xiaomi_mi-router-ax3000t-ubootmod-initramfs-recovery.itb ):
If successful, proceed from guide's point 8.
Basically, if you have OpenWrt U-Boot installed, then you need to use firmware files for ubootmod instead of the files for the default bootloader during UART flashing.