Çok geç oldu ama belki ihtiaycı olan biri olablir diye yazıyorum
İnstascan tüüm telefon modellerinde çalışır

   let scanner = new Instascan.Scanner({
   
   video: document.getElementById('preview'),
  
   continuous: true,
   mirror: false,
   
   captureImage: false,
   backgroundScan: true,
 
   refractoryPeriod: 1000,

   scanPeriod: 2
});

scanner.addListener('scan', function (content, image) {
 
 var sipno = content;
        var islem = "qrsorgu";
        $.post("ajax.php",{sipno:sipno,islem:islem},function(gonderVeri){
                               $('#sonuc').html(gonderVeri);
              
                 }); 
  
});

let cameraList = []; 

Instascan.Camera.getCameras().then(function (cameras) {
  
   this.cameraList = cameras;
   cameras.forEach(element => {
      
      let cameraList = document.getElementById("cameras");
      let option = document.createElement("option");
      option.text = element.id;
      option.value = element.id;
      cameraList.add(option);
      scanner.start(cameras[0])
   });
}).catch(() => console.error(e));

document.getElementById("cameras").addEventListener("change", event => {
  
   scanner.start(this.cameraList.find(c => c.id == event.target.value));
})