The gyro permission request doesn't work on iOS since it's not tied to user input.
If you're feeling brave, you can paste this into your phone's javascript console to add a button that requests permission.
var b=document.createElement('button');
b.textContent='Gyro';
b.style='position:fixed;z-index:999';
b.onclick=()=>{DeviceOrientationEvent.requestPermission();b.remove()};
document.body.appendChild(b);
var b=document.createElement('button'); b.textContent='Gyro'; b.style='position:fixed;z-index:999'; b.onclick=()=>{DeviceOrientationEvent.requestPermission();b.remove()}; document.body.appendChild(b);