What are good options for PCR testing in Bangkok, particularly near Silom, for travel to London?

A user is seeking recommendations for PCR test providers in Bangkok, specifically near Silom, as they need it for a flight to London. They mention that obtaining tests has become more challenging recently due to a surge in cases. Commenters suggest DR. Donna as a reliable option for same-day test results and clarify that an antigen test might not be sufficient for entry to the UK.