I want to create a shortcode for chart.js, when I add this code without function in a page then it works fine, however, When I add this code in fuction.php it breaks the site. I already have tried my methods.

function chartJS_shortcode(){
?><canvas id="myChart" width="400" height="400"></canvas><?php

<script>
    const ctx = document.getElementById('myChart').getContext('2d');
    const myChart = new Chart(ctx, {
        type: 'bar',
        data: {
            labels: ['Red', 'Blue', 'Yellow', 'Green', 'Purple', 'Orange'],
            datasets: [{
                label: '# of Votes',
                data: [12, 19, 3, 5, 2, 3],
                backgroundColor: [
                    'rgba(255, 99, 132, 0.2)',
                    'rgba(54, 162, 235, 0.2)',
                    'rgba(255, 206, 86, 0.2)',
                    'rgba(75, 192, 192, 0.2)',
                    'rgba(153, 102, 255, 0.2)',
                    'rgba(255, 159, 64, 0.2)'
                ],
                borderColor: [
                    'rgba(255, 99, 132, 1)',
                    'rgba(54, 162, 235, 1)',
                    'rgba(255, 206, 86, 1)',
                    'rgba(75, 192, 192, 1)',
                    'rgba(153, 102, 255, 1)',
                    'rgba(255, 159, 64, 1)'
                ],
                borderWidth: 1
            }]
        },
        options: {
            scales: {
                y: {
                    beginAtZero: true
                }
            }
        }
    });
    </script>

}

add_shortcode("chartJS", "chartJS_shortcode");