Still available from Washington State: https://sayyescovidhometest.org/
And from federal government: https://www.covid.gov/tests
If you have the iHealth test
the expiration date has been extended by 3 months. https://ihealthlabs.com/pages/news
If you have the Flowflex test,
the expiration date has been extended by 4 months. https://www.aconlabs.com/flowflex-covid-19-antigen-home-test-new-shelf-life-extension/
To see the other at-home tests and possible expiration date extensions: https://www.fda.gov/medical-devices/coronavirus-covid-19-and-medical-devices/home-otc-covid-19-diagnostic-tests#list