templateUrl

The URL of the file that contains the revised template. The URL must point to a template (max size: 1 MB) that's located in an Amazon S3 bucket or a Systems Manager document. CloudFormation generates the change set by comparing this template with the stack that you specified. The location for an Amazon S3 bucket must start with https://. URLs from S3 static websites are not supported.

Conditional: You must specify only TemplateBody or TemplateURL.