Follow the steps below add page numbers in a PDF document:
1. Go to Document -> Header & Footer -> Add
2. Click on the position that you want to put the page numbers. You can either select a position on header or footer.
3. Click Page number
4. You can select the page number format by clicking on the “Page Number Format” dropdown box and also change the value on “Start Numbering At” field -> Click OK to confirm
5. You can also click on “Other” button and view other special fields
6. Go back to Header & Footer screen, hit Apply and verify the page numbers on the header/footer.