how to make a pdf unfillable?
['Step 1: Open the document in Acrobat. In Adobe Acrobat, choose the Fill & Sign or Prepare Form tool and select a file to upload. ... ', "Step 2: Select File > Print. Once you have completed the form, you're ready to flatten it. ... ", 'Step 3: Select the PDF printer. ... ', 'Step 4: Save to specified location.']