Safari stopped working.

Try double clicking the Home button or swipe up from the bottom of the screen and swipe Safari upwards. Go to Settings/Safari and clear History and Website Data. Open Safari and test.

Safari - Clear the history and cookies on your iPhone, iPad, or iPod touch. https://support.apple.com/en-us/HT201265

Safari website data on your iPhone or iPad - How to clear. https://www.imore.com/how-to-view-history-clear-website-data-cookies

Try this URL. https://www.opera.com

Restart the router.

Try suggestions given here: https://support.apple.com/guide/safari/if-you-cant-open-a-website-ibrw1071/mac

Check your Wifi or the VPN you have connected, or just restart your system