Can I reopen a prior year Turbo Tax? Specifically, I want to re-open my 2018 Turbo Tax. My problem is that my Turbo Tax 2018 PDF doesn't show my IRA details.

Not sure what information you want, but lines 4a and 4b on your 1040 tell you your distribution and how much was taxed. 

You would have to download the .tax2018 data file and install the 2018  Desktop program to open it to see the actual entries.  If you paid for Online you can ask for the Desktop program.   You can download the tax file for free.  Then you need to install the Desktop program.

After you get the program installed the first thing to do before you open your tax return .tax file is to update the program and install any state programs you had. Then open your file. So you first might need to start a fake return to be able to download the state program (go to FILE - NEW).

If you didn't pay for the Online version you will have to buy the Desktop program download.  You can buy the last 3 years of Turbo Tax here,

https://turbotax.intuit.com/personal-taxes/past-years-products/

You will need a full Windows or Mac to install it on.

Save the tax file

https://ttlc.intuit.com/community/saving/help/how-do-i-save-my-turbotax-online-return-as-a-tax-data-file/00/25740