Hi evgenyguy,
We'd like to share some suggestions to get you started on the best path to resolve this. We would recommend starting with the troubleshooting in If Personal Hotspot is not working on your iPhone or iPad (Wi-Fi + Cellular) - Apple Support which has you go through the following and more.
Try connecting again after each step.
- Check that Personal Hotspot is turned on in Settings > Personal Hotspot. If you can't find or turn on Personal Hotspot, check that your wireless carrier enabled it and that your wireless plan supports it.
- Restart the iPhone or iPad that provides Personal Hotspot and the other device that needs to connect to Personal Hotspot.
- Make sure that you have the latest version of iOS or iPadOS.
- On the iPhone or iPad that provides Personal Hotspot, go to Settings > General > Transfer or Reset [Device] > Reset, then tap Reset Network Settings.
Use the steps below for more help with Personal Hotspot over Wi-Fi, USB, or Bluetooth.
If you continue to have issues, and followed this guidance in completion, the next step would be to contact Apple Support
Thanks for using Apple Support Communities.