[Vuejs]-How to use Vue's FunnelGraph.js with Python's Flask

Looks like a problem with FunnelGraph: it appears to throw this error when you define data as an array, although they have this example in their documentation. To work around it, define your data as an object:

var graph = new FunnelGraph({
    container: '#graph',
    gradientDirection: 'horizontal',
    displayPercent: true,
    direction: 'horizontal',
    data: {
        values: [12000, 5700, 360]
    },
});

graph.draw();

I also had to adjust your container selector to be #graph since that is what you have in the markup.