You can bypass the iCloud activation lock with DNS settings:
Select "Wi-Fi Settings" <In the Wi-Fi network list, click the "i" symbol of the WiFi network you want to connect to <Go to Network Settings <Enter your new DNS according to your location:
USA: 104.154.51.7
Europe: 104.155.28.90
Asia: 104.155.220.58
South America: 35.199.88.219
Australia and Oceania: 35.189.47.23
Finally, then reconnect your iPhone/iPad to WiFi <Complete.
Select "Wi-Fi Settings" <In the Wi-Fi network list, click the "i" symbol of the WiFi network you want to connect to <Go to Network Settings <Enter your new DNS according to your location:
USA: 104.154.51.7
Europe: 104.155.28.90
Asia: 104.155.220.58
South America: 35.199.88.219
Australia and Oceania: 35.189.47.23
Finally, then reconnect your iPhone/iPad to WiFi <Complete.