While COVIDTests.gov was expected to start accepting orders on Wednesday, an "Order free at-home tests" button was added Tuesday, which brings users to usps.com/covidtests to order four at-home free tests.

USA TODAY tested the site and got a message that "COVID-19 tests will start shipping in late January." The Postal Service will only send one set of  four free at-home coronavirus tests to valid residential addresses, the site said.

►COVID tests: How to get free at-home COVID-19 tests with insurance reimbursement.

A credit card isn't needed to order the free tests and there is no cost, unlike the insurance reimbursement program that started Saturday where many will have to submit receipts in order to get the tests for free.

"I had created a site to find vaccines earlier in the pandemic and knew that I would be able to use a lot of similar technology to create something to find at-home tests you can order online and get shipped," Eli told USA TODAY, adding he started ILVaccine.org in February 2021 after he saw how hard it was for his grandparents to get appointments.

The site tracks coronavirus tests online inventory at Amazon, CVS, Costco, Walgreens, Walmart, Target, Sam's Club and more and you can select the brand of test you're interested in.