Many DNS filtering companies like Control D, NextDNS, etc. allow personal devices to install iOS mobile config files to route their DNS requests via DoH on personal devices. Unfortunately, only enterprise subscribers can install these on iOS devices with DNSFilter and it requires Jamf or other enterprise management requirements.

Please allow personal devices to install these configs to route DNS via DoH to DNSFilter. I have switched to DNSFilter for my gateway, but have to still use Control D for my personal devices which I hate doing.