Pier 30/32 of Embarcadero is one of the few places in San Francisco that had opened up for free Covid testing. The location is opened 7 Days a week: 8am-6pm. An appointment is required, and that can be made online or through a phone call. You do not need an doctor's note nor medical insurance to get tested. Results are usually available in 2-5 days. For more information click here.