string to MFRC522::MIFARE_Key

Using Arduino Programming Questions
1

how to convert a string"FFFFFFFFFFFF" TO MFRC522::MIFARE_Key?

I TRIED LIKE THIS BUT ITS NOT WORKING

MFRC522::MIFARE_Key key;
char NewArray[13];
char a[2];
keyA.toCharArray(NewArray,13);
for (byte i = 0; i < 6; i++) {
a=char(NewArray[(i2)])+char(NewArray[((i2)+1)]);
key.keyByte = 0x(a);

  • }*
    I AM GETTING ERROR|
    incompatible types in assignment of 'int' to 'char [3]'
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