Custom tooltip Tooltip in chartview

[Refi]

I have set a custom tooltip using the code

    ChartView {
        id: chart
        anchors.fill: parent
        antialiasing: true
        ValueAxis {
            id: axisY
            tickCount: 3
        }
        DateTimeAxis{
               id: xTime
               gridVisible: false
           }
        ToolTip {
            id: id_toolTip
            contentItem: Text{
                color: "#21be2b"
            }
            background: Rectangle {
                    border.color: "#21be2b"
                }

        }
        SplineSeries{
            id: chartseries
            pointsVisible: true
            pointLabelsVisible: false
            useOpenGL: true
            axisX: xTime
            axisY: axisY
            onClicked: {
                id_toolTip.show("dd")
             }
        }

    }

It gives an error "TypeError: Property 'show' of object QQuickToolTip(0x37275d0) is not a function" when I click on the graph ..
But below mentioned code snippets work.

   chart.ToolTip.show("dd")

But I need custom tooltip

[Diracsbracket]

@Refi
Try this:

 ChartView {
        id: chart
        ...
        ToolTip {
            id: tip
            contentItem: Text{
                color: "#21be2b"
                text: tip.text
            }

            background: Rectangle {
                 color: "yellow"
                border.color: "red"
            }
        }
        LineSeries {
             ...
            onClicked: {
                tip.text = "dd"
                tip.visible = true
             }
        }
    }