Please follow this guide to setup Google and Cloudflare DNS servers instead of default ones.
1. Go to Settings.
2. Then tap on wi-fi.
3. Tap on the network you are currently connected to.
4. Tap on "Configure DNS".
5. Edit your DNS servers same as on the screenshot below and then tap on "Save" to save your settings.
Your new DNS are successfully installed now!
If you have any questions, or experience any issues while installing & setting up your IOS device to connect to the BoxPN VPN servers, please contact our Support Team anytime.