Get a document from erpnext with a standard format

Question

I'm facing an issue on frappe from last week. My requirement is the integration of docusign for embedded signing on erpnext. I almost completed all steps even the document attachement. But, when I send the document to docusign it sends by normal format without any headers. Which means I want like what we see in printview but I got like download pdf function. I get the document by this code.

server script:

html_content = frappe.get_print(doctype,docname, print_format='Standard')
pdf_data = base64.b64encode(html_content).decode('utf-8')
document={
    attachments: pdf_data //this for docusign attachement document. 
}