How do I print my full 2018 return? It's only showing 18 pages. Other answers I've seen on here have outdated information.

Well you are in a pickle right now ...  when you log in now all you can get is the PDF of the return as filed only.

Now the online program has gone dark for the next 6 weeks to change over to the 2019 program and the 2018 returns are being archived.   So if you did not save a PDF with the worksheets yet you will need to wait until the 2019 program goes live in early December.