JSFiddle - React, Tailwind, and code Playground

HTML

<button id="check">check</button>
<button id="req">request approval</button>

JavaScript

function checkIsApproved(){
  return navigator.mediaDevices.enumerateDevices()
    .then(infos =>{
      console.log([...infos].map(i=>i.label));
      return [...infos].some(info=>info.label!=="")
    });
}
check.onclick = e => {
  checkIsApproved().then(res=>alert('approved: ' + res));
};
req.onclick = e => {
 navigator.mediaDevices.getUserMedia({video:true}).then(s=>{});
}