Use a compatible RFID reader, authenticate if necessary, and send read commands via software or microcontroller in order to read a block from an RFID tag. Make sure that proper protocols are followed (LF, HF, UHF) and that data is retrieved securely. Integration of identification and access control systems enhances their efficiency.
as @ajb2k3 mentioned only one GPIO (the second one) is used for the RGB unit. So the other GPIO can still be used as input. I created an example which uses GPIO1 as input to control the color of the three RGB LEDs in the RGB unit.
See UIFlow2 Project Zone : M5Dial_RGBUnit_GPIO1_as_input_UIFlow2.0.4