This is my Owl component in Odoo 15. It is meant to load chart lib from CDN.

/** @odoo-module **/

import { loadAssets } from "@web/core/assets"; //not working.
import { loadJS } from "@web/core/assets"; //not working.
import { registry } from "@web/core/registry"
import { useService } from "@web/core/utils/hooks";

const { Component } = owl;
const { onWillStart, useRef, onMounted } = owl.hooks;

export class ChartRenderer extends Component {
    setup(){
      this.chartRef = useRef("chart")
      onWillStart(async ()=>{
      await loadJS("https://cdnjs.cloudflare.com/ajax/libs/Chart.js/4.4.0/chart.umd.min.js")
      //await loadAssets("/web/static/lib/Chart/Chart.js")
        })
        onMounted(()=>this.renderChart())
    }
    renderChart(){
       //body
    }
}

ChartRenderer.template = "my_module.ChartRenderer"

Upon loading the module, both loadJS() and loadAssets() within onWillStart function are throwing errors.

loadJS() error: 

"UncaughtPromiseError > ReferenceError

Uncaught Promise > loadJS is not defined.....

===========================
loadAssets() error: 

UncaughtPromiseError > TypeError

Uncaught Promise > Cannot use 'in' operator to search for 'bundles' in /web/static/lib/Chart/Chart.js.......

What am I not doing correctly? What is the correct way to load JS library within an Owl component?

Thanks.