Respond now at https://my2020census.gov/ The entire thing takes less than 10 minutes! 

The invitation you received in the mail has your census ID, a unique 12 digit code you will use to respond online, by phone or by mail. (Don't have your census ID? No problem, you don't need it to respond.) The census is easy, safe and important. Learn more via the city website now: http://www.montezumaiowa.org/city_info/2020_census.php