JSFiddle - React, Tailwind, and code Playground

JavaScript

// MAIN GRAPH PART

function graph(chartContainer, dataPoints1, dataPoints2)
{
  var chart = new CanvasJS.Chart(chartContainer,
  {
      title:{
        text: "PERFORMANCES CUMULÉES - NET B EN EUR *",
        verticalAlign: "top",
        horizontalAlign: "left",
        fontColor: "#2f4f4f",
        fontSize: 30,
        padding: 10,
        margin: 15,
        backgroundColor: "#FFFFE0",
        borderThickness: 1,
        cornerRadius: 5,
        fontWeight: "bold"
      },
      legend:{
        fontSize: 12,
        verticalAlign: "top",
        horizontalAlign: "center"
      },
      axisX:{  
              lineThickness: 0,
              tickThickness: 0,
              valueFormatString: "MM/YY",
              minimum: new Date(2006, 00, 05)
      },

      axisY: {
        
        tickThickness: 0,
        stripLines:[
      {                
        startValue:150,
        endValue:151,                
        color:"black"                      
      }
      ],
      				labelFormatter: function(e) {
      					return(e.value / 100 + "%");
   						}
              labelFontSize: 14,
              interval: 150,
              gridThickness: 0
      },
      
      data: [
      {        
        type: "spline",
        color: "rgb(85, 118, 180)",
        showInLegend: true,
        markerSize: 0,
        legendMarkerType: "spline",
        legendText: "FONDS",
        lineThickness: 2,
        dataPoints: dataPoints1,
      },
      {
        type: "spline",
        color: "rgb(185, 11, 18)",
        showInLegend: true,
        markerSize: 0,
        legendMarkerType: "spline",
        legendText: "BENCHMARK",
        lineThickness: 2,
        dataPoints: dataPoints2,
      }],
    });

chart.render();
}

// DATA POINTS IN THE PHP PAGE

<script src='JS/graph1.js'></script>
<script>
  var dataPoints1 = [
    <?php
      $id = 9;
      $values = graphQuery($id, $conn);
      graphDisplay($values);
    ?>
  ];
  var dataPoints2 = [
    <?php
      $id =...