It seems like you’ve requested a password change. No worries, if you are using your SSH key to enter you can change it anytime you wish.
Anyway, here is how you can actually change the Password for your root. Please read it and see if you’ve actually done anything to have this prompt appear.
Changing user password in Ubuntu is dead simple. In fact, it’s the same with any Linux distribution because you use the generic Linux command called passwd for this purpose.
If you want to change your current password, simply run this command in a terminal:
You’ll be asked to enter your current password and the new password twice.