Wifi

Here are several troubleshooting steps you can try:

1. Restart your iPhone and your Wi-Fi router: Restarting both your iPhone and your Wi-Fi router can often solve connectivity issues. To restart your iPhone, press and hold the power button until you see the "slide to power off" option. Slide the button to power off your iPhone, then turn it back on. To restart your Wi-Fi router, unplug it from the power source, wait 30 seconds, and plug it back in.
2. Check your Wi-Fi connection: Make sure that your iPhone is connected to the correct Wi-Fi network. Go to Settings > Wi-Fi, and check that your iPhone is connected to the network you want to use. If not, select the correct network and enter the password if prompted.
3. Forget the Wi-Fi network and reconnect: Sometimes, simply forgetting the Wi-Fi network and reconnecting can solve connectivity issues. Go to Settings > Wi-Fi, and tap the "i" icon next to the network you want to forget. Tap "Forget This Network," then reconnect to the network.
4. Reset network settings: Resetting your network settings can sometimes solve connectivity issues. Go to Settings > General > Reset > Reset Network Settings. This will erase all your Wi-Fi passwords and network settings, so make sure to have them handy before resetting.
5. Update your iPhone software: Make sure that your iPhone is running the latest version of iOS. Go to Settings > General > Software Update to check for any available updates.

Ref:

• Recommended settings for Wi-Fi routers and access points - Apple Support
• If your iPhone, iPad, or iPod touch won’t connect to a Wi-Fi network - Apple Support