I can't install grub2, what should I do?

Question

linux

here is a link to install a hornbeam on my device
https://4pda.ru/forum/index.php?showtopic=611095&v...
I always boot into the system through the hornbeam console as it is written in the article, a hornbeam that was partially installed through the bootloader recovery program .I'm tired of writing all this, I want to restore it, but I'm not a pro in this, so ..... that's what I get as an output - after the command sudo grub-install /dev/mmcblk0p1
Installation for the i386-efi platform.
efibootmgr: EFI variables are not supported on this system.
efibootmgr: EFI variables are not supported on this system.
Installation completed. There are no errors.