Can't get elevation from mapbox terrain webp

https://codesandbox.io/s/terrain-rgb-g4nym?file=/src/index.ts

import { TerrainRGB } from "@watergis/terrain-rgb";

const url = "https://api.mapbox.com/raster/v1/mapbox.mapbox-terrain-dem-v1/{z}/{x}/{y}.webp?sku=10149h63PJzgC&access_token=pk.eyJ1IjoiZGV2LWFhYyIsImEiOiJjbDI5MGl5N3QwZGNlM2NuN3l6bGtxaTd6In0.ornsESAnvKKQedUSw2fKyA";
const trgb = new TerrainRGB(url, 512);
const coordinate = [78.34336242946887, 22.133570853753696];
const zoom = 14;

trgb.getElevation(coordinate, zoom).then((elevation: number | undefined) => {
  const doc = document.getElementById("app");
  if (doc) {
    doc.innerHTML = `
    <h1>Hello terrain-rgb!</h1>
    <div>
      <ul>
        <li>URL: ${url}</li>
        <li>Longitude: ${coordinate[0]}</li>
        <li>Latitude: ${coordinate[1]}</li>
        <li>Zoom level: ${zoom}</li>
        <li>Elevation: ${elevation}</li>
      </ul>
    </div>
    <div>
    Look the repository at <a href= "https://github.com/watergis/terrain-rgb" >watergis/terrain-rgb</a>
    </div>
    `;
  }
});

watergis / terrain-rgb

Can't get elevation from mapbox terrain webp #9