A developer needs to configure PingGateway to protect a legacy backend that does not support TLS. To ensure end-to-end security, PingGateway must receive traffic over HTTPS, validate an OpenID Connect session, and then terminate TLS before forwarding the request over a secure internal network segment. If the backend response contains absolute URLs with 'http', which PingGateway feature should be used to ensure the client receives 'https' links?