JSFiddle - React, Tailwind, and code Playground

HTML

<video playsinline autoplay style="object-fit:cover; width:630px; height:1200px"></video>

CSS

* {
    margin: 0;
    padding: 0;
}

JavaScript

// Prefer camera resolution nearest to 1280x720.
var constraints = { 
	audio: false, 
  video: {
    facingMode: { 
      exact: "environment" // exact: "user"
    }
  }
  
}; 

navigator.mediaDevices.getUserMedia(constraints)
.then(function(mediaStream) {
  var video = document.querySelector('video');
  video.srcObject = mediaStream;
  video.onloadedmetadata = function(e) {
    video.play();
  };
})
.catch(function(err) { console.log(err.name + ": " + err.message); }); // always check for errors at the end.