Most modern MacBooks come with a USB-C port for charging and file transfer, so if you want to exchange files between your SD card and your MacBook Air, what you need is an SD card reader that connects to the USB-C port.
If you need an SD card reader, you can purchase one that is compatible with your MacBook Air on the Apple official website or other shopping websites. If you don't know how to choose it, you can check for the model of your MacBook Air and then choose an SD card adapter with a higher transfer speed than your SD card.