Iplay50 mini pro root and lineage OS (help me..)

Hello.
My iplay50 mini pro is in a reboot loop.

I recently saw the lineage OS installation page and ran it.

How to Install LineageOS GSI ROM on iPlay 50 Mini/Pro/Max

That page.

Root permission has been obtained, and factory initialization has been made.
I was USB debugging has not been enabled in the Device’s Administrator privileges option.
Problems occurred while installing lineage OS in that state.

The connection is verified in Android SDK, but it doesn’t seem to get fastboot permission.

It reboots every 5 seconds, and the factory initialization screen appears, but even if you reset it, it only reboots.

I tried to overwrite the genuine OS with the sp flash tool, but when I load the MT6789_Android_scatter.txt file, I get 5079 error.

I was so tired from three days of internet search.

Help me..