error opening page: hotspot login cannot open the page because it is not connected to the internet

Hi liu_hannah,

We recommend that you try the steps in the link below if you're unable to connect to the internet via your Personal Hotspot.

If Personal Hotspot is not working on your iPhone or iPad (Wi-Fi + Cellular)

To perform the recommended troubleshooting steps via the link above, complete the steps in the section titled "If you can't connect to Personal Hotspot with Wi-Fi."

On the device that provides Personal Hotspot, go to Settings > Personal Hotspot, then follow these steps:

1. Make sure that Allow Others to Join is on. 

2. Remember the device's Wi-Fi network name and password that appear on this screen. If you want to change the Wi-Fi network name, learn how to change your device name.

3. If you're using an iPhone 12 model or later, iPad Pro 11-inch (3rd generation or later), iPad Pro 12.9-inch (5th generation or later), or iPad mini (6th generation), turn on Maximize Compatibility.* Then try connecting your devices again to your Personal Hotspot.

4. Stay on this screen until you connect your other device to the Wi-Fi network. 

On the device that needs to connect to Personal Hotspot, follow these steps:

1. Turn Wi-Fi off and back on.

2. Make sure that you connect to the correct Wi-Fi network. The network name is the same as the iOS device that provides Personal Hotspot and the Personal Hotspot icon  might appear next to it.

3. If you see a password error when you try to join Personal Hotspot, check the Wi-Fi password: On the device that provides Personal Hotspot, go to Settings > Personal Hotspot to see the Wi-Fi password.

* When you turn on Maximize Compatibility, internet performance and Wi-Fi security might be reduced for devices connected to the hotspot.

We recommend the steps above because they will show you what to do if you can't connect to your Personal Hotspot.

If you're having problems viewing webpages, try the steps here: If Safari isn't loading websites or quits on your iPhone, iPad, or iPod touch

Please let us know the outcome after giving the above steps a try.

Thanks for using the Apple Support Communities.

Cheers!