As I have written some posts before.
- Setup a TFTP Server for recovery, using one of the RB01 images, e.g. 1.0.71_INT.
- Connect to UART, 115200 Baud
- Start recovery/debrick procedure
- As soon as erasing starts, unplug the power cable
- Plug in power cable again, you should end up on a UBoot terminal
- Enable UART, Telnet, SSH, just to be sure. setenv uart_en=1; setenv telnet_en=1; setenv ssh_en=1
- Place image on TFTP server (Not sure, but I think I used openwrt-mediatek-mt7622-xiaomi_redmi-router-ax6s-initramfs-recovery.itb)
- tftpboot openwrt-mediatek-mt7622-xiaomi_redmi-router-ax6s-initramfs-recovery.itb
- This should end up in a booted openwrt
- Install to flash using sysupgrade
As far as I remember that's all I did to get it running on a locked RB01 from 11/21. Try it on your own risk!