mi 11 lite 5G (renoir) - miui 12.5.7 global - can't find boot.img to patch for root with magisk

[Redrum777]

I have a Mi 11 lite 5g (renoir), I unlocked the bootloader and rooted with magisk. I downloaded the RENOIRGlobal_V12.5.7.0.RKIMIXM update and before installing it I tried to restore the magisk image with no success. the phone works but I no longer have root and fastboot mode appears with a single orange word "fastboot". miflash cannot find the phone and on reboot there is no more lock even though it tells me the device has unlocked the OEM. in the ROM zip (12.5.7) I can't find the boot.img to fix it. can someone help me? could i switch to this miui 13 and patch its boot.img?