This example needs to be updated since the "data.sparkfun.com" is no longer available. https://github.com/espressif/arduino-esp32/blob/57b27cd800321e03c33f80bc5f2bf16aafb39b18/libraries/WiFi/examples/WiFiClient/WiFiClient.ino#L14 Change to any other working host.