The AWS Cloud9 IDE offers a rich code-editing experience with support for several programming languages and runtime debuggers, and a built-in terminal. It contains a collection of tools that you use to code, build, run, test, and debug software and helps you release software to the cloud.
You access the AWS Cloud9 IDE through a web browser.
The AWS Command Line Interface (awscli) will be installed and configured on the AWS Cloud9 Instance. If the instructions refer to the awscli use the one that is installed on the Cloud9 instance.
Make sure that you execute the awscli (aws) as ubuntu. It is only configured for this user on the Cloud9 instance.