In some situtations you might have a user which needs access to sudo but you dont know or have a password, for example when you only have ssh-key access to a server.
To enable this we just need to modify the sudoers file:
Open Sudoers File
sudo vim /etc/sudoers
Find the line containing includedir /etc/sudoers.d and add the following and save
theusersusernamehere ALL=(ALL) NOPASSWD: ALL