missing bootstrap.js

I use Sencha Architect 3.1 to create a Ext 5.x Blank Project, one panel is added

index.html is as follows:


<script id="microloader" type="text/javascript" src="bootstrap.js"></script>

however, when I run the index.html in a browser, Chrome reported bootstrap.js did not find (image enclosed), and I really can't find this js in the saved project folder (image enclosed), is there anything I missed in the Sencha Architect setup?

missing bootstrap.js