If the IRS sent you a refund check or they cashed your check for payment, you have a confirmation. If you filed with Turbotax in 2019, the program will have timestamped when the return was accepted (e-file), but I don't think it can check the status of a mailed return.
Of course, a call to the IRS (ugh!) could answer the question, but if the return was done manually and they say they don't have it, the IRS will need to tell you how to refile.
