Waiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 7473 (unattended-u^Cr)... 3s code example

Example 1: E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?

sudo kill -9 PID
sudo rm /var/lib/dpkg/lock-frontend
sudo apt update

Example 2: E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?

ps aux | grep -i apt