Developed RFC 8252-compliant loopback redirect support for the Application Password Flow in the peterwilsoncc/wordpress-develop repository, enabling HTTP redirects for loopback addresses such as 127.0.0.1 and [::1]. The work involved updating PHP-based validation logic to accept loopback IPs while maintaining strict security by rejecting insecure protocols for non-loopback addresses. Comprehensive unit tests were added to verify correct handling of loopback redirects and to enforce security constraints. This feature resolved issue #57809, aligning the application password flow with RFC guidance and improving interoperability, security posture, and developer experience for localhost OAuth workflows in a back end environment.