In AWS, you need Access Key ID and Secret Access Key to call AWS functions. If you don't have access keys, you can create them by using the IAM console at 

Followings are the process to get your access key ID and secret access key:

Open the IAM console at

→ Navigation Menu → Users → Choose your IAM user name → Open the Security credentials tab

→ Choose Create access key

→ To download the key pair, choose Download .csv file. Store the .csv file with keys in a secure location