The website, covidtests.gov, is not a scam or fake, it is a legit government website. COVIDTests.gov, which was announced a few days ago by the White House, is a website that you can use to order four free at-home COVID-19 rapid antigen tests per household. The website is now up and running.
There may be fake Free COVID-19 Test Kits websites created by scammers that look similar to www.covidtests.gov. But, the only other official government website for ordering free rapid tests is: special.usps.com/testkits.