GRUB update

Not sure I understand. Give more details.

Are you having problems with your boot manager?
If not then it would not be necessary to change your version.
I see I have /usr/sbin/update-grub2 as well as /usr/sbin/update-grub.

Usually the install of a new linux kernel will automatically run update-grub. If you install another operating system on the same system you might want to run grub-update.

running 'sudo apt update && sudo apt upgrade' will make sure all your packages (including grub) are up to date.

After any change in hardware or operating system, run this command:
sudo update-grub
Running this command unnecessarily does no harm.

It is automatically run when Software Updater does its thing.

As for running a different version of grub, refer to the search
feature of this forum for more expert advice.

George Langford

$ grub-install -V
grub-install (GRUB) 2.02-2ubuntu8.21+9.0trisquel4

As Geshmy told you, unless you are facing some problem (what problem?), just install the updates Trisquel should regularly propose you.