Use Python to programmatically save PDFs, just like a PDF reader

Question

I have a PDF template that I pre-populate with Python. I tried using PyPDF2, pdfrw and now I am using fillpdf because it's the simplest to use and produces the same results.

My problem is that all the PDFs pre-populated with Python are not being accepted by e-signature providers like DocuSign and OneSpan...

I found this solution: https://www.valleycollege.edu/about-sbvc/offices/campus-technology-services/documents/blank_pdf_issue.pdf

But that requires that I open the file manually and print as PDF. Is there a way to do this automatically with Python? Is there another solution?

from fillpdf.fillpdfs import write_fillable_pdf    
data = {
        "Name": "Value1",
    }
    input_pdf_file = "input.pdf"
    output_pdf_file = "filled.pdf"

    write_fillable_pdf(input_pdf_file, output_pdf_file, data, flatten=True)