Install grub-emu by entering the following commands in the terminal:
sudo apt update sudo apt install grub-emu
Description:
GRand Unified Bootloader, version 2 (emulated version)
This package contains grub-emu, an emulated version of GRUB. It is only provided for debugging purposes.
Homepage: http://www.gnu.org/software/grub/
Version: 2.02-2ubuntu8
Section: universe/admin