Access key and Secret key issue during SMS setup

Hi SMS connector/.ova is installed at ESXi/vCeter. In almost final step to configure AWS SMS Connector, Access Key and Secret Key are entered, and then it should ask vCenter credential question based on protocol, but it did not go that step, instead I got the below error message. In addition, the IAM account get associated permit for the migration. Did I miss some step? How to resolve the issue? Thank you!

Error message:

Error: An internal error occurred. Confirm that your AWS credentials and vCenter credentials are correct. If this problem persists, please contact AWS support.