reset root password ubuntu 20.04 code example
Example 1: set password to root ubuntu 20.04
$ sudo -i
$ passwd root
new password:...
confirm password:...
Example 2: default root password ubuntu 18.04
$ sudo passwd
Example 3: change password ubuntu 20.04
open your terminal
ctrl-alt-t
passwd username
If you have admin password you can change all passwd of users
su -
passwd username