1040SR is larger type 1040 on 3 pages ad prints if you are 65 years old.
All Turbo Tax versions have 1040-SR. You automatically get the 1040SR if you or your spouse is 65 or older.
The 1040SR is EXACTLY the same as the regular 1040 just bigger type so it prints on 3 pages instead of 2. And the Standard Deduction is on page 4. They both use the same instructions and tax calculations.
Form 1040:
https://www.irs.gov/pub/irs-pdf/f1040.pdf
Form 1040SR
https://www.irs.gov/pub/irs-pdf/f1040s.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.
If you use the Desktop program you can switch to forms and the Info Wks part II has a selection to select 1040SR or not. You can not change it in the Online versions. In the Online version if you want to use the regular 1040 form, you can print out the 1040SR and copy the amounts onto a blank 1040 and then mail your return.