Bluetooth pairing Apple wireless keyboard model A1314 to MacOS Big Sur
Posting a question & solution all in one:
Simply hold down the power button on the A1314 keyboard until the green light blinks. If you don't see that right away, release & try again. Once the green light is blinking, continue holding down the power button until you see a prompt on the MacOS screen asking you to type 6 numbers & press return on the keyboard. Do that & your keyboard will then be paired. Enjoy!