In your local machine, create a containers.json file with the following contents. 

[
{
"Description": "Entrust PKIaaS Virtual Machine AMI file",
"Format": "ova",
"UserBucket": {
"S3Bucket": "$AWS_S3_BUCKET",
"S3Key": "$OVA_FILE"
}
}
]

In the file contents, replace:

For example:

[
{
"Description": "Entrust PKIaaS Virtual Machine AMI file",
"Format": "ova",
"UserBucket": {
"S3Bucket": "pkiaas-vm",
"S3Key": "pkiaas-vm-prod-us.ova"
}
}
]