Do I need a QR code for my vaccination card as an American traveling through Singapore?

An American traveler inquiring about the necessity of a QR code for their vaccination card while transiting through Singapore received mixed responses. Some commenters stated that it is not needed and that a plain vaccination card suffices, while others mentioned that specific airlines, like Singapore Air, require a QR code, which can be obtained through a government website in California. Overall, the necessity of the QR code appears to depend on the airline and specific travel requirements.