The Biden administration on Tuesday quietly launched its website for Americans to request free at-home COVID-19 tests, a day before the site was scheduled to officially launch.

The website, COVIDTests.gov, now includes a link for Americans to order up four at-home tests per residential address, to be delivered by the U.S. Postal Service. It marks the latest step by President Joe Biden to address criticism of low inventory and long lines for testing during a nationwide surge in COVID-19 cases due to the omicron variant.

A White House official said the website is “currently in its beta phase” and operating at a “limited capacity ahead of its official launch." The website will officially launch mid-morning Wednesday, the official said.

Biden announced last month that the U.S. would purchase 500 million at-home tests to launch the program and on Thursday the president announced that he was doubling the order to 1 billion tests.

But Americans shouldn’t expect a rapid turnaround on the orders and they will have to plan ahead and request the tests well before they meet federal guidelines for when to use a test.

The White House said “tests will typically ship within 7- 12 days of ordering” through USPS, which reports shipping times of 1-3 days for its first-class package service in the continental United States.

Officials emphasized that the federal website is just one way for people to procure COVID-19 tests, and shortages of at-home test kits have shown signs of easing as more supply has hit the market.

Since Saturday, private insurance companies have been required to cover the cost of at-home rapid tests, allowing Americans to be reimbursed for tests they purchase at pharmacies and online retailers. That covers up to eight tests per month.