What is the 24 hour rule for KLM?

KLM’s 24-hour rule allows passengers to cancel their booking within 24 hours of purchase for a full refund. This policy applies to all fare types booked directly with KLM. For assistance, contact KLM customer service: From the US: Call 1-804-853-9001 to speak with a representative.

Source: https://community.expensify.com/discussion/19802/help-agent-what-is-the-24-hour-rule-for-klm-service-suport/p1?new=1