In my Salesforce org, I’ve installed the eSignature app. I’ve successfully configured and activated the app user, and I’ve also created an envelope.

Now, I want to send a PDF file as an attachment to the client using that envelope. This should be done automatically through Apex, triggered after a specific action. The email should include the DocuSign envelope and attach related documents from the record.

What I need to know is: how can I use Apex to send an email to the customer, using the existing envelope and attaching the related existing documents?

Note:Is this possible to implement? Can it be done using only Apex, or with Flow, or both?