I'm following this tutorial step by step,forHere we clone the repo into a chmodded /var/www/[site_dir] folder.  Note that we switch to the www-data user before running the git clone  command. This is an important step because the deploy key we generated  is owned by the www-data user and it will only work for that user,  even if you are on the root.I need to switch to www-data user, but when I try sudo su - www-data ( or sudo su www-data ) I faced with This account is currently not available.I try ps aux and I see that the www-data user exists, Now I want to know how can I achieve that ? ( login with www-data user)
login with apache user
sudo;users;webserver;su