VirtualBox "sudo apt install openssh-server" ERROR after doing "sudo killall apt apt-get" it returns "apt: no process found apt-get: no process found"

Question

I'm a bit new here to AskUbuntu (this is my first post), but there is an extremely annoying problem when I try:

user@machine:/etc$ sudo apt install openssh-server 
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?`

This is annoying because I was trying to setup a Minecraft server and operate it via ssh but this is not letting me. I tryed sudo killall apt apt-get but its not letting me and returning:

user@machine:/etc$ sudo killall apt apt-get
apt: no process found 
apt-get: no process found

Do you reckon that I should update? VB (VirtualBox) always is saying update to newer version. This is not a copy of this question. I'm starting to think about if should log on as root, or if I should remove the machine or not.

It's so annoying. ):( I can't stand it!

Hi guys, I fixed it by installing it by sudo su then sudo apt install openssh-server