The IRS is showing the Verification of Non-filing letter because they have not yet processed your 2020 tax return. The 2020 transcript will not be available until sometime after the IRS processes the return, which might not be until a few months from now. I would think that the lender is aware that IRS processing is severely backlogged this year, and that it is taking months for tax returns to be processed. If the person you're dealing with doesn't know that, show them the information that DoninGA referenced on the IRS web site, or ask to speak to someone higher up (or find another lender). Perhaps they will accept a copy of your tax return that includes the Electronic Postmark, which shows that it was accepted. In the PDF from TurboTax, the Electronic Postmark page is at or near the end of the federal tax return.
