I’d like to see the final return. If I purchase your service and get the return, can I still come back to edit the file after I check the return?

You can print the return to review it and make changes if necessary before you e-file it.  You have to pay your fees before you can print.

https://ttlc.intuit.com/community/printing/help/can-i-print-a-copy-of-my-turbotax-online-return-before-i-file-it/00/26244

TurboTax stupidly "finishes" your return if you Print it.

You have to reopen it to resume with more  edits.

Use the bizarre command trick, "Add a State"

@benn333