The New York Times had a story about a particular rapid test called BinaxNOW from Abbott Laboratories that detects about 95% of the cases of Omicron. Other rapid tests are less accurate. And this article was helpful: Which Covid Test Should I Get? When Should I Test? What If I Can’t Find One? Answers About Testing and Omicron. Much of the getting supplies part applies to the US, of course, but some of the information should be globally helpful.