The Doppler Kubernetes Operator continuously synchronizes secrets, including PKCS12 certificates, between Doppler and a Kubernetes cluster. To use the Operator, first install it using Helm or kubectl, then import the PKCS12 certificate into Doppler. The Operator creates a custom resource in Kubernetes to store the synced secret. A service token is required for the Operator to access the secrets. The Operator mounts the certificate inside a container and verifies its metadata.