How to load a python script as an attachment to a aws:executeScript step as an attachement?

From https://docs.aws.amazon.com/systems-manager/latest/userguide/automation-action-executeScript.html I see that you can use an attachement to load code and modules to the execution step. However, it is not clear to me where this code would actually sit. The step only specifies the name of the attachment.

action: "aws:executeScript" inputs: Runtime: runtime Handler: "functionName" InputPayload: scriptInput: '{{parameterValue}}' Script: |- def functionName(events, context): ... Attachment: "scriptAttachment.zip"

in this example where do i put "scriptAttachment.zip" so that it can be access by the SSM Document when it runs?

I would appreciate an example so that I could 1.) load python scripts without them being part of the SSM Docuemnt and 2.) use python modules (i.e. Pandas) that are not part of the default library).