How do I get the PDF byte stream of all the documents within an envelope using the Apex Toolkit?

I can’t seem to find the right method to do this from the documentation:
https://developers.docusign.com/docs/salesforce/apex-toolkit-reference/documentservice.html

I’m looking for an Apex Toolkit equivalent way of doing this:
https://developers.docusign.com/docs/esign-rest-api/reference/envelopes/envelopedocuments/get/#:~:text=To%20retrieve%20a%20single%20document,just%20the%20certificate%20of%20completion.

Some sample code of how to do this is appreciated.