[Solved]-HighCharts - Angular, how to get y axis labels on the vertical lines drawn from x axis-Highcharts

one way to add labels for the inner grid lines would be to create a dummy series type scatter. this allows you to aim at a precise point on the graph and include only a datalabel for that series which will display the value.

  {
    type: 'scatter',
    data: [1, 50, 100, 200],
    color: 'transparent',
    datalabels: {
      enabled: true
    }
  }

now you have to set the added dummy scatter series to be invisible and not respond to mouse movement and not show the tooltip.

plotoptions: {
  series: {
      colorbypoint: false
  },
  scatter: {
      states:{
          inactive:{
              enabled: false
          }
      },
      datalabels:{
          enabled: true,
          padding: 1,
          allowoverlap: true,
          crop: false,
          overflow: 'allow',
      },
      enablemousetracking: false,
      showinlegend: false
  },

another way, if you are curious or if the above doesn't satisfy you, is to render the label. https://api.highcharts.com/class-reference/highcharts.svgrenderer#label

to select the exactly coordinates of a point, you can use x, y notation.

    data: [{x:0, y:1 }, {x:1, y:20}, 100, 200],