Not able to select camera

[Mav977]

I have used the 'Easy mode' and according to screenshots and demos, I should get the option to select my camera. But I don't get that option not only on my laptop but also on my mobile. Moreover, on mobile, the camera uses the front camera which is not user-friendly to scan qr codes. Could you please help me out..

<script src="https://unpkg.com/html5-qrcode" type="text/javascript"></script>
<center><div id="reader" style="width:300px"></div></center>

This is what I am getting

[ROBERT-MCDOWELL]

what do you call "options"? a select box with the list of devices?