Can't you just ask the friend where/how it was prepared?
If the 2017 return was prepared through H&R Block, then we can't help you obtain an H&R Block return. You would need to talk to H&R Block's Customer Support.
If it was prepared in TurboTax, however, or if you think it might have been, we can tell you how to look for the account with the return.
If you can't obtain a prior-year return or otherwise have problems verifying, you'll have to talk to someone at the IRS to see what you need to do to complete the IDverify process, and contact the IRS Taxpayer Advocate Service if you have any trouble. I left you info above on how to contact both.
