Creating downloadable pdf files in Storyline - an update on earlier methods

Hi there,

I've been trying to create this PDF here and have been able successfully tweak it. 

However, I've run into a separate issue: I was trying to flatten the PDF (so as to prevent it being changed after it was downloaded). However, this command didn't work (in my case):

form.flatten();

Does anyone know what can be done? Appreciate any support!

Thanks a lot,

John