Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 18894 (apt-get) code example

Example 1: E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?

ps aux | grep -i apt

sudo kill <process_id>
# Check if the process was killed by running the ‘ps aux | grep -i apt’ command. If it is still running, force kill it with SIGKILL signal:

sudo kill -9 <process_id>
# Another, easier way would be to use the killall command. This will kill all the instances of a running program:

sudo killall apt apt-get

Example 2: how to fix could not fix var lock /var/lib/dpkg/lock ubuntu

sudo rm /var/lib/apt/lists/lock