If you e-filed a return for the same tax filer from two different accounts, then only one of the returns will be accepted by the IRS ****IF**** ***AND*** ***ONLY*** ***IF*** the IRS computers find no errors in the return and accept the return. The second return will be rejected.
If you e-filed two different returns from the same account, then the first return filed was over written and is lost forever, with no possible way to recover it. If the lost return was already accepted by the IRS, then the only possible way to get a copy of that return is to pay the IRS for a copy of it. An actualy copy cost $50 while a transcript is free. For details see https://www.irs.gov/newsroom/how-to-get-tax-transcripts-and-copies-of-tax-returns-from-the-irs