Filling area between two lines - Chart.js v2

Question

I am trying to fill the area between two lines in a line chart using Chart.js. Like this:

There is already an answer here, that explains how to extend chartjs to do

Answer 1

Setting fill property to +1 of a dataset will set the backgroundColor from this line to the next line in dataset.

datasets: [{
        label: 'Systolic Guideline',
        data: [],
        fill: '+1',
        borderColor: '#FFC108',
        backgroundColor: 'rgba(255,193,8,0.2)'
      },
      {
        label: 'Diastolic Guideline',
        data: [],
        fill: true,
        borderColor: '#FFC108',
        backgroundColor: 'rgba(0,0,0,0)'
      }]

See this: https://www.chartjs.org/samples/latest/charts/area/line-datasets.html