Grub error installation failed

Hi there,I am a rookie to Nixos and am using it alongside Ubuntu. I tried to resolve the “installation of GRUB failed” issue by using some earlier Nixos issues, but nothing was getting in the way

Installing for i386-pc platform.
/nix/store/4ifsgb6ljch39yrshhcr5m8z3q5jzb8g-grub-2.12-rc1/sbin/grub-install: warning: this GPT partition label contains no BIOS Boot Partition; embedding won't be possible.
/nix/store/4ifsgb6ljch39yrshhcr5m8z3q5jzb8g-grub-2.12-rc1/sbin/grub-install: warning: Embedding is not possible.  GRUB can only be installed in this setup by using blocklists.  However, blocklists are UNRELIABLE and their use is discouraged..
/nix/store/4ifsgb6ljch39yrshhcr5m8z3q5jzb8g-grub-2.12-rc1/sbin/grub-install: error: will not proceed with blocklists.
/nix/store/dy6wk1rf6cyn2w9d5jmm9z2bwlp0vjbm-install-grub.pl: installation of GRUB on /dev/sda failed: No such file or directory
warning: error(s) occurred while switching to the new configuration

my partitions is like:

lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
sda      8:0    0 465,8G  0 disk 
├─sda1   8:1    0 232,8G  0 part 
├─sda2   8:2    0   477M  0 part 
└─sda3   8:3    0 232,5G  0 part /nix/store

sda1 is for ubuntu
sba2 is efi partition
sb3 is Nixos
this from my configuration.nix

 # Bootloader.
  boot.loader.grub.enable = true;
  boot.loader.grub.device = "/dev/sda";
  boot.loader.grub.useOSProber = true;

@tigheni were you able to find solution to this? I am getting the same error at the moment.

Despite nixos being installed successfully, it does not seem like applying changes to it work, since grub cannot be “refreshed” due to this error