Operatie Enigma [Operation Enigma]

As couriers for the resistance in the 2nd world war, your mail came across from which it can be deduced that the Germans want to drop a bomb on the hiding place of your comrades. You obviously want to let the rest of your resistance group know as soon as possible, so that they can look for shelter elsewhere. Since the decoding code changes every hour and a half, it must be done within that time. Find the encryption of the code and send a warning to your allies. Good luck!