American immigrant visa interview passed ... give a piece of paper and say it will take months to verify ... how can I receive it after a few months?

Did the landlord say background check? In the past, background checks took a long time, sometimes even two or three months, but after the Obama administration took office, new regulations were introduced, and the results could be obtained within two weeks.

If the visa officer only says to check your resume or something during the face-to-face interview, then you can get your passport normally, so don't worry.

So the landlord doesn't have to worry, just wait.