Add fontawesome 5 icon at runtime

add_fontawesome5_icon_at_runtime.js

// See https://fontawesome.com/how-to-use/font-awesome-api#icon
var iconDefinition = FontAwesome.findIconDefinition({
    prefix: 'fal',
    iconName: 'circle-notch'
});

var icon = FontAwesome.icon(iconDefinition, {
    classes: 'preloader-icon'
}).html;

$('body').append(icon);