Install the mongo shell on Ubuntu 18.04

Import the public key that will be used by the package management system.

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 2930ADAE8CAF5059EE73BB4B58712A2291FA4AD5
Create the list file /etc/apt/sources.list.d/mongodb-org-3.6.list for MongoDB using the command appropriate for your version of Ubuntu.

Ubuntu 18.04

echo "deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.6 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.6.list
Reload the local package database using the following command:

sudo apt-get update
Install the MongoDB shell.

sudo apt-get install -y mongodb-org-shell