Groovy: “Unable to locate package” while trying to install packages with APT

Run
sudo apt-get update

Example:root@2d91134ff240:/# groovy -v
bash: groovy: command not found
root@2d91134ff240:/# apt -y install groovy
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package groovy
root@2d91134ff240:/# apt -y install groovy
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package groovy

root@2d91134ff240:/#  apt-get update