Upload data to a PDF form file previously stored internally in the app

Good morning. Is there an extension or is it possible to edit a previously uploaded editable PDF form file in App Inventor using JavaScript code? Once edited, download or share it. By editing, I mean loading a field from the PDF from a variable or text box. Thank you very much.

Does it have to be a pdf ?

Good morning.
Thank you very much for your response. I really need to be able to upload a form-like PDF with editable fields, add the data at runtime from various processes, and then share the PDF with the field changes. Thank you again for your response.