There are basically 2 options for filing your 4868 form, efile the extenition with a number of IRS partners (including turbotax), or mail in the the 4868 form.
You cannot electronically upload the pdf to "efile" it. It may be easier just to mail it in to one of the centers specified on the form: https://www.irs.gov/pub/irs-pdf/f4868.pdf
