Assistance with Packer 1.5.4

I am trying to use for amazon ebs. I am receiving an error “Build ‘amazon-ebs’ errored: No valid credential sources found for AWS Builder.” In my environment I am not able to get access-key and secret-key well not easily anyway. I tried to use my IAM arn but that did not resolve the issue. Is there a way to get packer builds to run with out using an access-key / secret-key or IAM role arn?

How do you normally authenticate to AWS from your environment?

I would either ssh via my account or the ec2-user account but for the console its via the IAM role