aws-sdk:sesv2:sendEmail failing with BadRequestException

Inside a Step Function I am trying to send a simple email and I get the following error Service returned error code BadRequestException (Service: SesV2, Status Code: 400 Request ID: etc

Is there something wrong/missing? Could this be a permission problem? I'm testing it with a real email address (not user@mail.com)

This is my Parameters JSON "Content": { "Simple": { "Body": { "Text": { "Data": "Body" } }, "Subject": { "Data": "Test Email Send" } } }, "ReplyToAddresses": ["user@email.com"], "Destination": { "ToAddresses": ["user@email.com"] }