How to have line labels on both sides of a Y-axis?

Unfortunately, there isn't any inbuilt support for having labels on both sides of a Y-axis. Here are two suggested workarounds:

**1. Use endLabel for the end and MarkPoint for the start**

Example:

const dataset = [[150, 230, 224, 218, 135, 147, 260], [230, 160, 70, 135, 147, 140, 110], [135, 147, 260, 340, 290, 110, 90]];
const entity = ['Mangolia', 'Mitzerland','Torsica'];

const seriesList = [];
for (const index in dataset) {
  const row = dataset[index];
  seriesList.push({
    type: 'line',
    data: row,
    endLabel: {
      show: true,
      formatter: () => 'end label = ' + row[row.length - 1]
    },
    markPoint: {
      symbolSize: 0,
      label: {position: 'left'},
      data: [{coord: [0, row[0]], value: entity[index]}]
    }
  });
}

option = {
  xAxis: {
    type: 'category',
    data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
  },
  yAxis: {
    type: 'value'
  },
  series: seriesList
};

**2. Use Custom Component**

You can also create a custom component to achieve this. Here's an example using the ECharts extension:

import * as echarts from 'echarts/core';

echarts.registerCoordinateSystem('dual-y-axis', {
  create: function (ecModel, api) {
    var dualYAxis = new DualYAxis(ecModel, api);
    ecModel.coordinateSystemManager.registerCoordinateSystem(dualYAxis);
    return dualYAxis;
  },
  dimensions: ['y', 'y2']
});

class DualYAxis {
  constructor(ecModel, api) {
    this._model = ecModel;
    this._api = api;

    this._yAxisModels = [];
    this._yAxisAxes = [];
  }

  // ... other methods

  getAxis(dim) {
    return this[`_axis${dim}`];
  }

  getAxes() {
    return this._yAxisAxes;
  }

  getMin() {
    return Math.min.apply(null, this._yAxisAxes.map(function (axis) { return axis.min; }));
  }

  getMax() {
    return Math.max.apply(null, this._yAxisAxes.map(function (axis) { return axis.max; }));
  }
}

This is just a starting point, and you may need to modify it to meet your specific requirements.

Please note that these workarounds may not be as straightforward as using a built-in option, but they should be able to help you achieve the desired result.