unable to acquire dpkg frontend lock code example

Example 1: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?

ps aux | grep -i dpkg

// Kill processes which are running
sudo kill -9 

// Restart the accounts daemon
sudo systemctl restart accounts-daemon

Example 2: E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?

sudo lsof /var/lib/dpkg/lock
sudo lsof /var/lib/apt/lists/lock
sudo lsof /var/cache/apt/archives/lock

Example 3: how to fix could not fix var lock /var/lib/dpkg/lock ubuntu

sudo rm /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock

Example 4: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?

ps aux | grep -i apt