Make a prefilled PDF to save user entered data and do soap request.

We are prefilling a PDF with PDFbox with some userdata and that workes find. 

But we would like to prefill the PDF with data, then also add "Reader Extension" to the file, so a non-paying Acrobat Reader user can fill it in and save the form. Also it should be possible to send soap request from that form to get some more information. 

Right now we "Reader Extending" it, uploads it to a server. When a user open it, we prefill it from PDFbox, and we get this error (attching error message). 

Is it possible to add "Reader Extension" programmatic after you prefilled a form? What do you need to do that? Can you do that from the "Adobe Acrobat Pro DC" version? Or does it need to be done from an AEM server?