Hometech Alfa 7LM Plus bootloop error and can't access via adb/fastboot

My device is **Hometech Alfa 7LM Plus**. I made a mistake while rooting my device and now I can't boot it. I tried rooting my device, but TWRP did not support it, so I tried rooting without TWRP. I downloaded my device's stock ROM (not sure if it was safe or the right ROM, just the label was true) and copied boot.img (I don't remember the device's CPU model, so I am not sure I must copy boot.img or recovery.img or anything else) file to the device. Then I patched the stock ROM with Magisk in the device itself and flashed to the device patched_boot.img with fastboot. It flashed, but now I can't boot my device nor access recovery with power + volume keys or adb/fastboot (even if they don't connect or list the device). How can I fix that situation?