@edgarblythe,
Nary a sign of the form as of yet. As hightor indicated, a person will come round if you fail to respond. From what I remember of 2010, they place an envelope with the form under the door of your abode.
If still no answer, a person will come knocking at your door. If no answer, they'll slip a message under the door, letting you know they were there. A phone number will be given to call.
(yeah, that's what happened to me in 2010. I had failed to respond initially to the form they'd sent, so, a person showed up, put a note under my door...)
Then there is the after-census returns time. Random calls are made to confirm your answers.
When I went looking, I located the Fed's internet pages about this census.
https://2020census.gov/en/ways-to-respond.html
It seems you can fill out the info online.