This is still work in progress... Meanwhile you can contribute to this page?
<input type="text" class="js-range-slider" name="my_range" value="" />
let range = Material.Forms.initRangeSlider(document.querySelector(".aa"), {
start: 20,
range: {
min: 0,
max: 100,
},
});
alert(range.noUiSlider.get());