Create an on-device DNS proxy.
A DNS proxy provider is an app extension that implements DNS proxying. You should create a DNS proxy provider if you want to take responsibility for resolving all DNS queries on the system. Typically this involves forwarding the queries in a way that improves performance, reliability or security. For example, a DNS proxy provider might:
Forward DNS queries to a well-known Internet-wide DNS server
Talk to a DNS proxying service using DNS over HTTPS (DoH) or DNS over TLS (DoT)
Implement a completely custom DNS proxying protocol
DNS proxy providers are only supported on supervised iOS devices.