How implement CoreNFC in iOS 14 with swift

When im executed the next code in iPhone Xs with iOS 14:

   var session: NFCNDEFReaderSession?
    session = NFCNDEFReaderSession(delegate: self, queue: nil, invalidateAfterFirstRead: true)
    
    session?.alertMessage = "Hold your iPhone near the item to learn more about it."
    session?.begin()

I got the following error:

[CoreNFC] 00000002 83fe0180 -[NFCNDEFReaderSession _callbackDidBecomeActive]:218  Delegate does not implement -readerSessionDidBecomeActive: method

even having implemented the method:

func readerSessionDidBecomeActive(_ session: NFCNDEFReaderSession) {

}