Custom jquery function not working in view : Laravel

I'm trying to use a progressbar plugin, I've installed it using npm install progressbar.js & required it in my app.js file.

I have also defined my custom function - generate_circle() in my app.js file.

When I call my custom function generate_circle() in the view inside a script tag I get the error

Uncaught ReferenceError: generate_circle is not defined

in my console. The plugin files are loaded correctly because I can see the plugin code in the app.js file.so that is not the issue.

Can anybody help me with this?

This is how my app.js file look like

require('./bootstrap');
var ProgressBar = require('progressbar.js');
function generate_circle(){
    var circle = new ProgressBar.Circle('.box',{
        color: '#FF0000',
        strokeWidth: 5,
        trailColor: '#f4f4f4',
        fill: 'black',
        duration: 5000,
        warnings: true,
        from: { color: '#38ef7d' },
        to: { color: '#11998e' },
        step: function(state, circle, attachment) {
            circle.path.setAttribute('stroke', state.color);
        },
    });
    alert(1);
    circle.animate(1);
}

And this is my view :

--- header and other stuff --- 
<script src=""></script>
    <script>
        generate_circle();
    </script>
</body>
</html>

via Chebli Mohamed