The 1040SR is EXACTLY the same as the regular 1040 just bigger type so it prints on 3 pages instead of 2. They both use the same instructions and tax calculations
https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
When you print it will print on the 1040SR even if you see only the 1040 on the screen. You automatically get the 1040SR if you or your spouse is 65 or older. In the Desktop program you can tell it which one to print. You can't change it in the Online version.
For a couple of reasons I want to print in the 1040 format NOT the 1040SR format and changing my age would create other issues. I am using the CD Deluxe version on Windows. Is there no way to select between the two formats? Surely there is some provision for doing this!