Meaning
Secure checkout wording tells shoppers that payment happens through the store checkout process using supported security controls.
Where it fits
Use this term on a shipping page when the term affects delivery or fulfillment expectations. Keep the wording short, then link to the full policy or support path when the answer has exceptions.
This is educational copy guidance, not legal advice. Match the final wording to the store's actual policy, support capacity, and fulfillment process.