PHP 8.0 compatibility - TypeError: array_key_exists()

I run this error after upgrade PHP version to 8.0:

TypeError: array_key_exists(): Argument #2 ($array) must be of type array, null given a CRM_Core_Payment_Redsys->doTransferCheckout() (línia 211 de (...)/redsys/CRM/Core/Payment/Redsys.php).