Hi Bruce, for Gyroscope on IOS devices above 12.2 version, you will need to do the following:
1. Go to Settings > Safari
2. Scroll down to the Privacy & Security section
3. Enable Motion & Orientation Access
That’s it. Now you can go to the browser and open the page with the virtual tour.
You will find the gyroscope icon at the top left side.
Let me know if you have any more confusion.