I tried but i have nothing maybe its mining ? i need to put private key it in bitcoin core ? or Electrum ?
Did you mean it does not work while you use bitaddress offline? Because the hexadecimal private key with you will need to be converted to WIF, when wanted to convert it, it does not work? Or you are importing the hexadecimal directly?
If it did not work while converting it to WIF using bitaddress, that means it is not a valid private key.