Quote from webneedy on February 24, 2023, 8:49 am

The "safari cannot connect to server ipad" warning offers a number of connection issues with your iPad's Internet connection. The connection error could appear due to a number of issues, including a poor wireless network signal and the Wi-Fi functionality on your iPad being disabled. Although the error does not specify a particular issue, you can investigate issues that might be causing connection problems until you find the ideal solution.

Also read - https://webneedy.com/fix-not-registered-on-network-error-on-android/