persona upgrade migration | sed 's/\b\(.\)/\u\1/g' Overview API versioning via Persona-Version header, deprecated field migration, test against sandbox. Prerequisites - Completed setup - Valid Persona API key (sandbox or production) Instructions Step 1: Implementation Output - API versioning via Persona-Version header, deprecated field migration, test against sandbox. Error Handling | Error | Cause | Solution | |-------|-------|----------| | 401 Unauthorized | Invalid API key | Check PERSONA API KEY | | 429 Rate Limited | Too many requests | Implement backoff | | 404 Not Found | Wrong resourc…