Adding Chart.js line chart to Jinja2/Flask html page from JS file

I have the following code in a simple Bootstrap html file which displays a Chart.js line chart.

    <div class="card-block chartjs">
       <canvas id="line-chart" height="500"></canvas>
    </div>

The js file that contains the chart's setup looks like this:

$(window).on("load", function(){

    var ctx = $("#line-chart");

    var chartOptions = {
        responsive: true,
        maintainAspectRatio: false,
        legend: {
            position: 'bottom',
        },
        hover: {
            mode: 'label'
        },
        scales: {
            xAxes: [{
                display: true,
                gridLines: {
                    color: "#f3f3f3",
                    drawTicks: false,
                },
                scaleLabel: {
                    display: true,
                    labelString: 'Month'
                }
            }],
            yAxes: [{
                display: true,
                gridLines: {
                    color: "#f3f3f3",
                    drawTicks: false,
                },
                scaleLabel: {
                    display: true,
                    labelString: 'Value'
                }
            }]
        },
        title: {
            display: true,
            text: 'Chart.js Line Chart - Legend'
        }
    };

    var chartData = {
        labels: ["January", "February", "March", "April", "May", "June", "July"],
        datasets: [{
            label: "My First dataset",
            data: [65, 59, 80, 81, 56, 55, 40],
            fill: false,
            borderDash: [5, 5],
            borderColor: "#9C27B0",
            pointBorderColor: "#9C27B0",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }, {
            label: "My Second dataset",
            data: [28, 48, 40, 19, 86, 27, 90],
            fill: false,
            borderDash: [5, 5],
            borderColor: "#00A5A8",
            pointBorderColor: "#00A5A8",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }, {
            label: "My Third dataset - No bezier",
            data: [45, 25, 16, 36, 67, 18, 76],
            lineTension: 0,
            fill: false,
            borderColor: "#FF7D4D",
            pointBorderColor: "#FF7D4D",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }]
    };

    var config = {
        type: 'line',

        options : chartOptions,

        data : chartData
    };

    var lineChart = new Chart(ctx, config);
});

I would like to avoid using a separated javascript file and rather just have everything in my Jinja2/Flask html page. A working example can be found in this tutorial, this is the same way that I would like to follow. I have tried to copy any paste the js part to my html page and put between <script> tags, but unfortunately it doesn't work.

Here is how I tried:

# in my jinja2/flask html page
<div class="card-body collapse in">
    <div class="card-block chartjs">
        <canvas id="line-chart" height="500"></canvas>
    </div>
</div>
<script>
    var ctx = $("#line-chart");
    var chartOptions = {
        responsive: true,
        maintainAspectRatio: false,
        legend: {
            position: 'bottom',
        },
        hover: {
            mode: 'label'
        },
        scales: {
            xAxes: [{
                display: true,
                gridLines: {
                    color: "#f3f3f3",
                    drawTicks: false,
                },
                scaleLabel: {
                    display: true,
                    labelString: 'Month'
                }
            }],
            yAxes: [{
                display: true,
                gridLines: {
                    color: "#f3f3f3",
                    drawTicks: false,
                },
                scaleLabel: {
                    display: true,
                    labelString: 'Value'
                }
            }]
        },
        title: {
            display: true,
            text: 'Chart.js Line Chart - Legend'
        }
    };

    // Chart Data
    var chartData = {
        labels: ["January", "February", "March", "April", "May", "June", "July"],
        datasets: [{
            label: "My First dataset",
            data: [65, 59, 80, 81, 56, 55, 40],
            fill: false,
            borderDash: [5, 5],
            borderColor: "#9C27B0",
            pointBorderColor: "#9C27B0",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }, {
            label: "My Second dataset",
            data: [28, 48, 40, 19, 86, 27, 90],
            fill: false,
            borderDash: [5, 5],
            borderColor: "#00A5A8",
            pointBorderColor: "#00A5A8",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }, {
            label: "My Third dataset - No bezier",
            data: [45, 25, 16, 36, 67, 18, 76],
            lineTension: 0,
            fill: false,
            borderColor: "#FF7D4D",
            pointBorderColor: "#FF7D4D",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }]
    };

    var config = {
        type: 'line',

        // Chart Options
        options : chartOptions,

        data : chartData
    };

    // Create the chart
    var lineChart = new Chart(ctx, config);
});
</script>

Unfortunately I'm not so familiar with JS and don't have more ideas about what should I do to display the chart in my Flask app. What do I need to implement to make it work?