Right now you can order up to four free COVID At-Home Test Kits from the U.S. Department of Health & Human Services. Even if you already ordered four two other times you can grab another set of four.
The COVID at-home test kits are completely free, you will not need to enter any health insurance information, no credit card required, and shipping is free.
By clicking that same link above you can see if the tests you have are on the list of ones they have extended the expiration dates.
I got the free tests twice before but when I filled out the form, it told me I had reached the maximum for my address. Has their site not been updated?