I am trying to unlock bootloader on my Samsung A40 with Android software tools. I have installed software tools through Android SDK Manager in Android Studio. Adb lists devices:
However when I enter bootloader by typing adb reboot bootloader my device doesn't show with command fastboot devices:
I have tried installing drivers from Samsung site and through Android Studio Google drivers but neither worked. I installed drivers manually through device manager too.
I tried doing same commands in VM with Debian 10 but with same result.
I have tried flashing TWRP with Odin too but I got error: custom binary (vbmeta) blocked by oem lock.
I tried different USB ports too and a different cable.