Signed document with form fields

I have a fillable PDF, which is send to sign through ESign REST API. After the document is signed I would like to download it and retrieve form fields data for further processing. Is it possible to keep form fields after PDF is signed or the only way is to call formData API?

Before sending pdf to Adobe I've got a bunch of form fields that I'm able to process, but after downloading signed document there is only a signature field.