Download and install following library from arozcan
Set the Pin for the RST and i2c address!
#define RST_PIN 6 // Arduino UNO // #define RST_PIN 14 // D5 on NodeMCU // 0x28 is i2c address of the NFC Reader. Check your address with i2cscanner if not match. MFRC522 mfrc522(0x28, RST_PIN); // Create MFRC522 instance.