@ikoz, there's 2 unsolved problems:

1. My phone is in a non-warranty state, ~ 1 year currently; Also, in my country there's no any RMA by OnePlus, Oppo and other china-companies .
2. BROM mode is needed to use MTK Client. OnePlus is locked BROM mode on Android 12 and you cannot backup and restore partitions on 12 and higher OS's versions.

So, I ran into this problem when the phone went into bootloop - it seems to work, but I can't do anything about it. I'm looking for more serious solutions - some say MSM Tool is only suitable for Snapdragons (I have Mediatek), but I can't even try out this program - it requires authorization. Something tells me that it will solve my problem.

Recently I've bricked my phone and some people recommend me to search the "specialists", but I cannot do this.

I've read about I can unbrick my phone on MediaTek processor via MSM Tool or some similar tool. So, is it true? And where I can find this this tool?

I'll be glad for your response.

P.S.: Recently I've flash incorrect recovery.img and boot.img on Android 12 and my phone is in bootloop (attempt to load broken Recovery). Fastboot and Recovery doesn't works. BROM mode is locked.
P.S.: I do not find the most proper topic for my question, sorry about this.