(NEXSTAR) – Earlier this week, the White House and the U.S. Postal Service rolled out the online ordering for Americans to request four free at-home COVID-19 test kits. If you’re planning to sell yours online for some extra cash, you likely won’t have any luck.

Amazon, eBay, and Facebook have all imposed restrictions on users trying to sell COVID-19 tests, as well as other COVID-related materials like masks.

If you search Amazon for at-home COVID tests, you’ll see pages of results, including the brand’s own tests. What you won’t see, however, are unverified sellers, an Amazon spokesperson tells Nexstar.

Before COVID test kits are available for purchase through Amazon, the company verifies “the sellers as an authorized manufacturer and/or distributor and perform product compliance reviews.”

“This includes a review of the product packaging, COVID-19 test kit insert with instructions for use, product fact sheets, and invoices. Additionally, every COVID-19 test kit is required to have received Emergency Use Authorization from the U.S. Food and Drug Administration,” the Amazon spokesperson explains.

While tests can be purchased on Amazon, they cannot be found on eBay or Facebook Marketplace.

In a statement shared with Nexstar, an eBay spokesperson says its platform “does not allow the sale of Covid19 Rapid Antigen tests on our marketplace across North America, and we are making every effort to ensure that anyone who sells on our platform follows local laws and eBay policies.”

The online marketplace says it has already removed or blocked over 85 million listings for violating eBay’s policies related to COVID as of August 2021.

According to Facebook’s COVID-19 and Vaccine Policy, the platform is “working to remove COVID-19 content that contributes to the risk of real-world harm.” Among examples of content being removed is the “sale of test kits and related goods.” The policy goes on to explain the decision was made to “protect against exploitation of this crisis for financial gain.”

Those trying to sell tests online could face the same fate as two brothers from Tennessee who hoarded thousands of bottles of hand sanitizer in March 2020. Reports say online marketplaces, like Amazon and eBay, removed their listings and threatened others trying to do the same could lose their accounts.

For those looking to buy a COVID test online, the Better Business Bureau recommends researching the seller before making a purchase. You can also order your four free at-home testing kits from the White House and the U.S. Postal Service, or have your health insurance cover the costs for tests you purchase on your own.