Hi there dougstevenson,
Thank you for posting to Apple Support Communities.
We understand that Personal Hotspot is not working for you. To begin with, we recommend ensuring that your iPhone is updated to the latest version of iOS. Before updating, we recommend backing up your iPhone first. These articles can be of help. When you back up, you can back up using a Mac or PC rather than iCloud if you choose.
How to back up your iPhone, iPad, and iPod touch
Update iOS on iPhone
"Use these steps first
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."
If Personal Hotspot is not working on your iPhone or iPad (Wi-Fi + Cellular) - Apple Support
That should help. Let us know if you have any questions.
Take care.