What is the 24 hour rule for Lufthansa?

KLM’s 24-hour rule is a rule that allows a passenger to cancel or change their Flight bookings within the first 24 hours at no extra charge. You can do so by navigating to the KLM Manage Trips or by calling them directly, However, if you make any modification after these 24 hours, you will be charged for a KLM cancellation/change Flight fee that may vary depending on several reasons.