How to: Zeppelin + boto3 + AWS Credentials
Zeppelin can be installed in several ways , which could point to the root cause of the issue : 

via the tar file download - in that case @mootmoot's way is right . boto3 should be configured with the appropriate python interpreter  
via docker image - in that case you need to add the python module to the docker image itself : 

2.a. you can use 'docker exec -i -t  bash\sh(your preference)'
2.b pip install
I have a VM with Zeppelin that is a shared environment. I want to add boto3 so I can do some python against AWS. Since zeppelin is running as a service, where would I add the AWS credentials? Would it be in the root's home? Or the home account the service is running under? Or within Zeppelin's user can they supply their own AWS credentials? 
I did pip install boto3 on the OS and then tried in a notebook to import it and I got a ModuleNotFoundError: No module named 'boto3' error.
Looking for guidance from anyone who has gotten their zeppelin to work with AWS.