Unfortunately, if you made the mistake of doing a "non-filer" form to get the stimulus faster, then your regular return is treated as an amended return, and amended returns take 16+ weeks to process under normal circumstance. No idea how long they will take this year with the shut downs. Then, it may not show up as a transcript until a few weeks after it is processed.
To get an idea of when the return might be processed, you can check here.
https://www.irs.gov/filing/wheres-my-amended-return
The underwriter may be understanding, or they may be required to follow their policies to the letter and deny a loan. We can't say, you will have to ask the underwriter. (Who is not the person who is taking your application, that is a lower level person with zero authority.)
