idempotency keys for critical API operations, dont you think?

Hey everyone, I'm wrestling with a tricky problem in our microservices architecture. We have a few payment-related APIs that are critical, and we absolutely cannot afford duplicate operations. I've been looking into idempotency keys as a solution. Basically, the client sends a unique key with each request, and the server uses that key to make sure the operation only runs once. It seems like a good fit, but I'm curious about the best ways to generate and manage these keys on the client side. Also, how do we handle them efficiently on the server side, especially when we're getting a lot of traffic? What have you all found works best for implementing idempotency in those really important API flows?