How to create Forecast Chart using ECharts

I want to create a forecast chart with Actual (a line chart) and projected values (a dotted chart). Here is an example made with Excel:

I want to create the same chart using the ECharts library but I couldn't find any example to use from their web page https://echarts.apache.org/examples/en/:

It would be very helpful if there is an approach to build this chart using javascript, I don't mind using other libraries like ChartJs if they have this possibility.

try this.

option = {
    xAxis: {
        type: 'category',
        data: [20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1]
    },
    yAxis: {
        type: 'value'
    },
    series: [{
        data: [0, 20, 30, 45, 40, 50, 51, 52, 50, 49, 56, 55],
        type: 'line',
        smooth: true,
        lineStyle: {
            color: 'red'
        }
    }, {
        data: [null, null, null, null, null, null, null, null, null, null, null, 55, 50, 49, 48],
        type: 'line',
        smooth: true,
        lineStyle: {
            color: 'blue',
            type: 'dashed'
        }
    }]
};

It's a very simple example but it should solve your issue. I didn't add the legend, but you should be able to do that without any issues.