How to setup Constructor options in Buefy while using CDN?

Question

I'm new to Buefy and Vue.

I'm using the following libraries through CDN: bulma0.9.3 vue2.6.14 buefy0.9.13 fontawesome5.15.4

Two files index.html and index.js are being used.

I'm tried to set the defaultIconPack to fontawesome globally by following the instructions given at Constructor options - Buefy documentation. But the icons in index.html defaults to mdi and not to fontawesome.

index.js

Vue.use(Buefy, {
        defaultIconPack: 'fas'
    });
let vm = new Vue({
    el: "#app",
    delimiters: ["[[", "]]"],
    data: {
        data: [],
        columns: []
    },
    mounted: function () {
        document.getElementById('main').classList.add('is-active');
    },
    methods: {},
    computed: {}
})

Please advise.