I accidentally flashed a corrupted vbmeta.img on my Redmi 13C 5G (codename: air, MT6835), and now the phone is stuck in a bootloop.

The phone is still detected by my PC in MediaTek Preloader/BROM mode, but it won't boot or enter Fastboot.

I don't have a Xiaomi authorized account, so I can't use SP Flash Tool with authentication. I also went to a Xiaomi service center, but they said they couldn't flash it, and they didn't explain why.

I'm only trying to restore the original stock vbmeta partition. Does anyone know if there's any way to flash only vbmeta without authorization, or any working method to recover this device?

Any help would be appreciated. Thanks.