you'd have to embed a storyline file containing the text entry field for each instance where you want to input text. storyline would have to store the value using javascript to something like localstorage in the browser (https://community.articulate.com/discussions/rise-360/adding-a-text-box-for-user-input-in-rise360). you'd then have to have a final storyline at the end that reads all the stored values using javascript and builds the pdf file on the fly.
it doesnt seem like articulate will add text entry themselves, you have to do it yourself.
