Use this endpoint when a customer needs to change their existing username — for example, after an email change, rebranding, or correcting a previous entry.
This ensures that each customer's username remains unique and tied to their verified email identity.
Authorization: Bearer YOUR_TOKEN
Expected Behavior:
- On success, the username will be updated, and a message will confirm that verification is required. To complete the process, you need to verify the new username using the Confirm Customer Username Change endpoint.
- If the request is unauthorized or invalid, the system will respond with an error message.